1# SPDX-License-Identifier: GPL-2.0 2# Select 32 or 64 bit 3config 64BIT 4 bool "64-bit kernel" if "$(ARCH)" = "x86" 5 default "$(ARCH)" != "i386" 6 help 7 Say yes to build a 64-bit kernel - formerly known as x86_64 8 Say no to build a 32-bit kernel - formerly known as i386 9 10config X86_32 11 def_bool y 12 depends on !64BIT 13 # Options that are inherently 32-bit kernel only: 14 select ARCH_WANT_IPC_PARSE_VERSION 15 select CLKSRC_I8253 16 select CLONE_BACKWARDS 17 select GENERIC_VDSO_32 18 select HAVE_DEBUG_STACKOVERFLOW 19 select KMAP_LOCAL 20 select MODULES_USE_ELF_REL 21 select OLD_SIGACTION 22 select ARCH_SPLIT_ARG64 23 24config X86_64 25 def_bool y 26 depends on 64BIT 27 # Options that are inherently 64-bit kernel only: 28 select ARCH_HAS_GIGANTIC_PAGE 29 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 30 select ARCH_USE_CMPXCHG_LOCKREF 31 select HAVE_ARCH_SOFT_DIRTY 32 select MODULES_USE_ELF_RELA 33 select NEED_DMA_MAP_STATE 34 select SWIOTLB 35 select ARCH_HAS_ELFCORE_COMPAT 36 37config FORCE_DYNAMIC_FTRACE 38 def_bool y 39 depends on X86_32 40 depends on FUNCTION_TRACER 41 select DYNAMIC_FTRACE 42 help 43 We keep the static function tracing (!DYNAMIC_FTRACE) around 44 in order to test the non static function tracing in the 45 generic code, as other architectures still use it. But we 46 only need to keep it around for x86_64. No need to keep it 47 for x86_32. For x86_32, force DYNAMIC_FTRACE. 48# 49# Arch settings 50# 51# ( Note that options that are marked 'if X86_64' could in principle be 52# ported to 32-bit as well. ) 53# 54config X86 55 def_bool y 56 # 57 # Note: keep this list sorted alphabetically 58 # 59 select ACPI_LEGACY_TABLES_LOOKUP if ACPI 60 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI 61 select ARCH_32BIT_OFF_T if X86_32 62 select ARCH_CLOCKSOURCE_INIT 63 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 64 select ARCH_HAS_DEBUG_VIRTUAL 65 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE 66 select ARCH_HAS_DEVMEM_IS_ALLOWED 67 select ARCH_HAS_EARLY_DEBUG if KGDB 68 select ARCH_HAS_ELF_RANDOMIZE 69 select ARCH_HAS_FAST_MULTIPLIER 70 select ARCH_HAS_FILTER_PGPROT 71 select ARCH_HAS_FORTIFY_SOURCE 72 select ARCH_HAS_GCOV_PROFILE_ALL 73 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION 74 select ARCH_HAS_MEM_ENCRYPT 75 select ARCH_HAS_MEMBARRIER_SYNC_CORE 76 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 77 select ARCH_HAS_PMEM_API if X86_64 78 select ARCH_HAS_PTE_DEVMAP if X86_64 79 select ARCH_HAS_PTE_SPECIAL 80 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 81 select ARCH_HAS_COPY_MC if X86_64 82 select ARCH_HAS_SET_MEMORY 83 select ARCH_HAS_SET_DIRECT_MAP 84 select ARCH_HAS_STRICT_KERNEL_RWX 85 select ARCH_HAS_STRICT_MODULE_RWX 86 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 87 select ARCH_HAS_SYSCALL_WRAPPER 88 select ARCH_HAS_UBSAN_SANITIZE_ALL 89 select ARCH_HAS_DEBUG_WX 90 select ARCH_HAVE_NMI_SAFE_CMPXCHG 91 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI 92 select ARCH_MIGHT_HAVE_PC_PARPORT 93 select ARCH_MIGHT_HAVE_PC_SERIO 94 select ARCH_STACKWALK 95 select ARCH_SUPPORTS_ACPI 96 select ARCH_SUPPORTS_ATOMIC_RMW 97 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 98 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 99 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 100 select ARCH_SUPPORTS_LTO_CLANG if X86_64 101 select ARCH_SUPPORTS_LTO_CLANG_THIN if X86_64 102 select ARCH_USE_BUILTIN_BSWAP 103 select ARCH_USE_QUEUED_RWLOCKS 104 select ARCH_USE_QUEUED_SPINLOCKS 105 select ARCH_USE_SYM_ANNOTATIONS 106 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 107 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 108 select ARCH_WANTS_DYNAMIC_TASK_STRUCT 109 select ARCH_WANT_HUGE_PMD_SHARE 110 select ARCH_WANT_LD_ORPHAN_WARN 111 select ARCH_WANTS_THP_SWAP if X86_64 112 select BUILDTIME_TABLE_SORT 113 select CLKEVT_I8253 114 select CLOCKSOURCE_VALIDATE_LAST_CYCLE 115 select CLOCKSOURCE_WATCHDOG 116 select DCACHE_WORD_ACCESS 117 select EDAC_ATOMIC_SCRUB 118 select EDAC_SUPPORT 119 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 120 select GENERIC_CLOCKEVENTS_MIN_ADJUST 121 select GENERIC_CMOS_UPDATE 122 select GENERIC_CPU_AUTOPROBE 123 select GENERIC_CPU_VULNERABILITIES 124 select GENERIC_EARLY_IOREMAP 125 select GENERIC_ENTRY 126 select GENERIC_FIND_FIRST_BIT 127 select GENERIC_IOMAP 128 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP 129 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC 130 select GENERIC_IRQ_MIGRATION if SMP 131 select GENERIC_IRQ_PROBE 132 select GENERIC_IRQ_RESERVATION_MODE 133 select GENERIC_IRQ_SHOW 134 select GENERIC_PENDING_IRQ if SMP 135 select GENERIC_PTDUMP 136 select GENERIC_SMP_IDLE_THREAD 137 select GENERIC_STRNCPY_FROM_USER 138 select GENERIC_STRNLEN_USER 139 select GENERIC_TIME_VSYSCALL 140 select GENERIC_GETTIMEOFDAY 141 select GENERIC_VDSO_TIME_NS 142 select GUP_GET_PTE_LOW_HIGH if X86_PAE 143 select HARDIRQS_SW_RESEND 144 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 145 select HAVE_ACPI_APEI if ACPI 146 select HAVE_ACPI_APEI_NMI if ACPI 147 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 148 select HAVE_ARCH_AUDITSYSCALL 149 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE 150 select HAVE_ARCH_JUMP_LABEL 151 select HAVE_ARCH_JUMP_LABEL_RELATIVE 152 select HAVE_ARCH_KASAN if X86_64 153 select HAVE_ARCH_KASAN_VMALLOC if X86_64 154 select HAVE_ARCH_KFENCE 155 select HAVE_ARCH_KGDB 156 select HAVE_ARCH_MMAP_RND_BITS if MMU 157 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT 158 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT 159 select HAVE_ARCH_PREL32_RELOCATIONS 160 select HAVE_ARCH_SECCOMP_FILTER 161 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 162 select HAVE_ARCH_STACKLEAK 163 select HAVE_ARCH_TRACEHOOK 164 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 165 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 166 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD 167 select HAVE_ARCH_VMAP_STACK if X86_64 168 select HAVE_ARCH_WITHIN_STACK_FRAMES 169 select HAVE_ASM_MODVERSIONS 170 select HAVE_CMPXCHG_DOUBLE 171 select HAVE_CMPXCHG_LOCAL 172 select HAVE_CONTEXT_TRACKING if X86_64 173 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING 174 select HAVE_C_RECORDMCOUNT 175 select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION 176 select HAVE_DEBUG_KMEMLEAK 177 select HAVE_DMA_CONTIGUOUS 178 select HAVE_DYNAMIC_FTRACE 179 select HAVE_DYNAMIC_FTRACE_WITH_REGS 180 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 181 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 182 select HAVE_EBPF_JIT 183 select HAVE_EFFICIENT_UNALIGNED_ACCESS 184 select HAVE_EISA 185 select HAVE_EXIT_THREAD 186 select HAVE_FAST_GUP 187 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE 188 select HAVE_FTRACE_MCOUNT_RECORD 189 select HAVE_FUNCTION_GRAPH_TRACER 190 select HAVE_FUNCTION_TRACER 191 select HAVE_GCC_PLUGINS 192 select HAVE_HW_BREAKPOINT 193 select HAVE_IDE 194 select HAVE_IOREMAP_PROT 195 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 196 select HAVE_IRQ_TIME_ACCOUNTING 197 select HAVE_KERNEL_BZIP2 198 select HAVE_KERNEL_GZIP 199 select HAVE_KERNEL_LZ4 200 select HAVE_KERNEL_LZMA 201 select HAVE_KERNEL_LZO 202 select HAVE_KERNEL_XZ 203 select HAVE_KERNEL_ZSTD 204 select HAVE_KPROBES 205 select HAVE_KPROBES_ON_FTRACE 206 select HAVE_FUNCTION_ERROR_INJECTION 207 select HAVE_KRETPROBES 208 select HAVE_KVM 209 select HAVE_LIVEPATCH if X86_64 210 select HAVE_MIXED_BREAKPOINTS_REGS 211 select HAVE_MOD_ARCH_SPECIFIC 212 select HAVE_MOVE_PMD 213 select HAVE_MOVE_PUD 214 select HAVE_NMI 215 select HAVE_OPTPROBES 216 select HAVE_PCSPKR_PLATFORM 217 select HAVE_PERF_EVENTS 218 select HAVE_PERF_EVENTS_NMI 219 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI 220 select HAVE_PCI 221 select HAVE_PERF_REGS 222 select HAVE_PERF_USER_STACK_DUMP 223 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT 224 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 225 select HAVE_REGS_AND_STACK_ACCESS_API 226 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION 227 select HAVE_FUNCTION_ARG_ACCESS_API 228 select HAVE_SOFTIRQ_ON_OWN_STACK 229 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR 230 select HAVE_STACK_VALIDATION if X86_64 231 select HAVE_STATIC_CALL 232 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION 233 select HAVE_PREEMPT_DYNAMIC 234 select HAVE_RSEQ 235 select HAVE_SYSCALL_TRACEPOINTS 236 select HAVE_UNSTABLE_SCHED_CLOCK 237 select HAVE_USER_RETURN_NOTIFIER 238 select HAVE_GENERIC_VDSO 239 select HOTPLUG_SMT if SMP 240 select IRQ_FORCED_THREADING 241 select NEED_SG_DMA_LENGTH 242 select PCI_DOMAINS if PCI 243 select PCI_LOCKLESS_CONFIG if PCI 244 select PERF_EVENTS 245 select RTC_LIB 246 select RTC_MC146818_LIB 247 select SPARSE_IRQ 248 select SRCU 249 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE) 250 select SYSCTL_EXCEPTION_TRACE 251 select THREAD_INFO_IN_TASK 252 select USER_STACKTRACE_SUPPORT 253 select VIRT_TO_BUS 254 select HAVE_ARCH_KCSAN if X86_64 255 select X86_FEATURE_NAMES if PROC_FS 256 select PROC_PID_ARCH_STATUS if PROC_FS 257 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI 258 259config INSTRUCTION_DECODER 260 def_bool y 261 depends on KPROBES || PERF_EVENTS || UPROBES 262 263config OUTPUT_FORMAT 264 string 265 default "elf32-i386" if X86_32 266 default "elf64-x86-64" if X86_64 267 268config LOCKDEP_SUPPORT 269 def_bool y 270 271config STACKTRACE_SUPPORT 272 def_bool y 273 274config MMU 275 def_bool y 276 277config ARCH_MMAP_RND_BITS_MIN 278 default 28 if 64BIT 279 default 8 280 281config ARCH_MMAP_RND_BITS_MAX 282 default 32 if 64BIT 283 default 16 284 285config ARCH_MMAP_RND_COMPAT_BITS_MIN 286 default 8 287 288config ARCH_MMAP_RND_COMPAT_BITS_MAX 289 default 16 290 291config SBUS 292 bool 293 294config GENERIC_ISA_DMA 295 def_bool y 296 depends on ISA_DMA_API 297 298config GENERIC_BUG 299 def_bool y 300 depends on BUG 301 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 302 303config GENERIC_BUG_RELATIVE_POINTERS 304 bool 305 306config ARCH_MAY_HAVE_PC_FDC 307 def_bool y 308 depends on ISA_DMA_API 309 310config GENERIC_CALIBRATE_DELAY 311 def_bool y 312 313config ARCH_HAS_CPU_RELAX 314 def_bool y 315 316config ARCH_HAS_CACHE_LINE_SIZE 317 def_bool y 318 319config ARCH_HAS_FILTER_PGPROT 320 def_bool y 321 322config HAVE_SETUP_PER_CPU_AREA 323 def_bool y 324 325config NEED_PER_CPU_EMBED_FIRST_CHUNK 326 def_bool y 327 328config NEED_PER_CPU_PAGE_FIRST_CHUNK 329 def_bool y 330 331config ARCH_HIBERNATION_POSSIBLE 332 def_bool y 333 334config ARCH_SUSPEND_POSSIBLE 335 def_bool y 336 337config ARCH_WANT_GENERAL_HUGETLB 338 def_bool y 339 340config ZONE_DMA32 341 def_bool y if X86_64 342 343config AUDIT_ARCH 344 def_bool y if X86_64 345 346config KASAN_SHADOW_OFFSET 347 hex 348 depends on KASAN 349 default 0xdffffc0000000000 350 351config HAVE_INTEL_TXT 352 def_bool y 353 depends on INTEL_IOMMU && ACPI 354 355config X86_32_SMP 356 def_bool y 357 depends on X86_32 && SMP 358 359config X86_64_SMP 360 def_bool y 361 depends on X86_64 && SMP 362 363config X86_32_LAZY_GS 364 def_bool y 365 depends on X86_32 && !STACKPROTECTOR 366 367config ARCH_SUPPORTS_UPROBES 368 def_bool y 369 370config FIX_EARLYCON_MEM 371 def_bool y 372 373config DYNAMIC_PHYSICAL_MASK 374 bool 375 376config PGTABLE_LEVELS 377 int 378 default 5 if X86_5LEVEL 379 default 4 if X86_64 380 default 3 if X86_PAE 381 default 2 382 383config CC_HAS_SANE_STACKPROTECTOR 384 bool 385 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT 386 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) 387 help 388 We have to make sure stack protector is unconditionally disabled if 389 the compiler produces broken code. 390 391menu "Processor type and features" 392 393config ZONE_DMA 394 bool "DMA memory allocation support" if EXPERT 395 default y 396 help 397 DMA memory allocation support allows devices with less than 32-bit 398 addressing to allocate within the first 16MB of address space. 399 Disable if no such devices will be used. 400 401 If unsure, say Y. 402 403config SMP 404 bool "Symmetric multi-processing support" 405 help 406 This enables support for systems with more than one CPU. If you have 407 a system with only one CPU, say N. If you have a system with more 408 than one CPU, say Y. 409 410 If you say N here, the kernel will run on uni- and multiprocessor 411 machines, but will use only one CPU of a multiprocessor machine. If 412 you say Y here, the kernel will run on many, but not all, 413 uniprocessor machines. On a uniprocessor machine, the kernel 414 will run faster if you say N here. 415 416 Note that if you say Y here and choose architecture "586" or 417 "Pentium" under "Processor family", the kernel will not work on 486 418 architectures. Similarly, multiprocessor kernels for the "PPro" 419 architecture may not work on all Pentium based boards. 420 421 People using multiprocessor machines who say Y here should also say 422 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 423 Management" code will be disabled if you say Y here. 424 425 See also <file:Documentation/x86/i386/IO-APIC.rst>, 426 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 427 <http://www.tldp.org/docs.html#howto>. 428 429 If you don't know what to do here, say N. 430 431config X86_FEATURE_NAMES 432 bool "Processor feature human-readable names" if EMBEDDED 433 default y 434 help 435 This option compiles in a table of x86 feature bits and corresponding 436 names. This is required to support /proc/cpuinfo and a few kernel 437 messages. You can disable this to save space, at the expense of 438 making those few kernel messages show numeric feature bits instead. 439 440 If in doubt, say Y. 441 442config X86_X2APIC 443 bool "Support x2apic" 444 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) 445 help 446 This enables x2apic support on CPUs that have this feature. 447 448 This allows 32-bit apic IDs (so it can support very large systems), 449 and accesses the local apic via MSRs not via mmio. 450 451 If you don't know what to do here, say N. 452 453config X86_MPPARSE 454 bool "Enable MPS table" if ACPI 455 default y 456 depends on X86_LOCAL_APIC 457 help 458 For old smp systems that do not have proper acpi support. Newer systems 459 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 460 461config GOLDFISH 462 def_bool y 463 depends on X86_GOLDFISH 464 465config RETPOLINE 466 bool "Avoid speculative indirect branches in kernel" 467 default y 468 help 469 Compile kernel with the retpoline compiler options to guard against 470 kernel-to-user data leaks by avoiding speculative indirect 471 branches. Requires a compiler with -mindirect-branch=thunk-extern 472 support for full protection. The kernel may run slower. 473 474config X86_CPU_RESCTRL 475 bool "x86 CPU resource control support" 476 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) 477 select KERNFS 478 select PROC_CPU_RESCTRL if PROC_FS 479 help 480 Enable x86 CPU resource control support. 481 482 Provide support for the allocation and monitoring of system resources 483 usage by the CPU. 484 485 Intel calls this Intel Resource Director Technology 486 (Intel(R) RDT). More information about RDT can be found in the 487 Intel x86 Architecture Software Developer Manual. 488 489 AMD calls this AMD Platform Quality of Service (AMD QoS). 490 More information about AMD QoS can be found in the AMD64 Technology 491 Platform Quality of Service Extensions manual. 492 493 Say N if unsure. 494 495if X86_32 496config X86_BIGSMP 497 bool "Support for big SMP systems with more than 8 CPUs" 498 depends on SMP 499 help 500 This option is needed for the systems that have more than 8 CPUs. 501 502config X86_EXTENDED_PLATFORM 503 bool "Support for extended (non-PC) x86 platforms" 504 default y 505 help 506 If you disable this option then the kernel will only support 507 standard PC platforms. (which covers the vast majority of 508 systems out there.) 509 510 If you enable this option then you'll be able to select support 511 for the following (non-PC) 32 bit x86 platforms: 512 Goldfish (Android emulator) 513 AMD Elan 514 RDC R-321x SoC 515 SGI 320/540 (Visual Workstation) 516 STA2X11-based (e.g. Northville) 517 Moorestown MID devices 518 519 If you have one of these systems, or if you want to build a 520 generic distribution kernel, say Y here - otherwise say N. 521endif 522 523if X86_64 524config X86_EXTENDED_PLATFORM 525 bool "Support for extended (non-PC) x86 platforms" 526 default y 527 help 528 If you disable this option then the kernel will only support 529 standard PC platforms. (which covers the vast majority of 530 systems out there.) 531 532 If you enable this option then you'll be able to select support 533 for the following (non-PC) 64 bit x86 platforms: 534 Numascale NumaChip 535 ScaleMP vSMP 536 SGI Ultraviolet 537 538 If you have one of these systems, or if you want to build a 539 generic distribution kernel, say Y here - otherwise say N. 540endif 541# This is an alphabetically sorted list of 64 bit extended platforms 542# Please maintain the alphabetic order if and when there are additions 543config X86_NUMACHIP 544 bool "Numascale NumaChip" 545 depends on X86_64 546 depends on X86_EXTENDED_PLATFORM 547 depends on NUMA 548 depends on SMP 549 depends on X86_X2APIC 550 depends on PCI_MMCONFIG 551 help 552 Adds support for Numascale NumaChip large-SMP systems. Needed to 553 enable more than ~168 cores. 554 If you don't have one of these, you should say N here. 555 556config X86_VSMP 557 bool "ScaleMP vSMP" 558 select HYPERVISOR_GUEST 559 select PARAVIRT 560 depends on X86_64 && PCI 561 depends on X86_EXTENDED_PLATFORM 562 depends on SMP 563 help 564 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 565 supposed to run on these EM64T-based machines. Only choose this option 566 if you have one of these machines. 567 568config X86_UV 569 bool "SGI Ultraviolet" 570 depends on X86_64 571 depends on X86_EXTENDED_PLATFORM 572 depends on NUMA 573 depends on EFI 574 depends on X86_X2APIC 575 depends on PCI 576 help 577 This option is needed in order to support SGI Ultraviolet systems. 578 If you don't have one of these, you should say N here. 579 580# Following is an alphabetically sorted list of 32 bit extended platforms 581# Please maintain the alphabetic order if and when there are additions 582 583config X86_GOLDFISH 584 bool "Goldfish (Virtual Platform)" 585 depends on X86_EXTENDED_PLATFORM 586 help 587 Enable support for the Goldfish virtual platform used primarily 588 for Android development. Unless you are building for the Android 589 Goldfish emulator say N here. 590 591config X86_INTEL_CE 592 bool "CE4100 TV platform" 593 depends on PCI 594 depends on PCI_GODIRECT 595 depends on X86_IO_APIC 596 depends on X86_32 597 depends on X86_EXTENDED_PLATFORM 598 select X86_REBOOTFIXUPS 599 select OF 600 select OF_EARLY_FLATTREE 601 help 602 Select for the Intel CE media processor (CE4100) SOC. 603 This option compiles in support for the CE4100 SOC for settop 604 boxes and media devices. 605 606config X86_INTEL_MID 607 bool "Intel MID platform support" 608 depends on X86_EXTENDED_PLATFORM 609 depends on X86_PLATFORM_DEVICES 610 depends on PCI 611 depends on X86_64 || (PCI_GOANY && X86_32) 612 depends on X86_IO_APIC 613 select I2C 614 select DW_APB_TIMER 615 select APB_TIMER 616 select INTEL_SCU_PCI 617 select MFD_INTEL_MSIC 618 help 619 Select to build a kernel capable of supporting Intel MID (Mobile 620 Internet Device) platform systems which do not have the PCI legacy 621 interfaces. If you are building for a PC class system say N here. 622 623 Intel MID platforms are based on an Intel processor and chipset which 624 consume less power than most of the x86 derivatives. 625 626config X86_INTEL_QUARK 627 bool "Intel Quark platform support" 628 depends on X86_32 629 depends on X86_EXTENDED_PLATFORM 630 depends on X86_PLATFORM_DEVICES 631 depends on X86_TSC 632 depends on PCI 633 depends on PCI_GOANY 634 depends on X86_IO_APIC 635 select IOSF_MBI 636 select INTEL_IMR 637 select COMMON_CLK 638 help 639 Select to include support for Quark X1000 SoC. 640 Say Y here if you have a Quark based system such as the Arduino 641 compatible Intel Galileo. 642 643config X86_INTEL_LPSS 644 bool "Intel Low Power Subsystem Support" 645 depends on X86 && ACPI && PCI 646 select COMMON_CLK 647 select PINCTRL 648 select IOSF_MBI 649 help 650 Select to build support for Intel Low Power Subsystem such as 651 found on Intel Lynxpoint PCH. Selecting this option enables 652 things like clock tree (common clock framework) and pincontrol 653 which are needed by the LPSS peripheral drivers. 654 655config X86_AMD_PLATFORM_DEVICE 656 bool "AMD ACPI2Platform devices support" 657 depends on ACPI 658 select COMMON_CLK 659 select PINCTRL 660 help 661 Select to interpret AMD specific ACPI device to platform device 662 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. 663 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is 664 implemented under PINCTRL subsystem. 665 666config IOSF_MBI 667 tristate "Intel SoC IOSF Sideband support for SoC platforms" 668 depends on PCI 669 help 670 This option enables sideband register access support for Intel SoC 671 platforms. On these platforms the IOSF sideband is used in lieu of 672 MSR's for some register accesses, mostly but not limited to thermal 673 and power. Drivers may query the availability of this device to 674 determine if they need the sideband in order to work on these 675 platforms. The sideband is available on the following SoC products. 676 This list is not meant to be exclusive. 677 - BayTrail 678 - Braswell 679 - Quark 680 681 You should say Y if you are running a kernel on one of these SoC's. 682 683config IOSF_MBI_DEBUG 684 bool "Enable IOSF sideband access through debugfs" 685 depends on IOSF_MBI && DEBUG_FS 686 help 687 Select this option to expose the IOSF sideband access registers (MCR, 688 MDR, MCRX) through debugfs to write and read register information from 689 different units on the SoC. This is most useful for obtaining device 690 state information for debug and analysis. As this is a general access 691 mechanism, users of this option would have specific knowledge of the 692 device they want to access. 693 694 If you don't require the option or are in doubt, say N. 695 696config X86_RDC321X 697 bool "RDC R-321x SoC" 698 depends on X86_32 699 depends on X86_EXTENDED_PLATFORM 700 select M486 701 select X86_REBOOTFIXUPS 702 help 703 This option is needed for RDC R-321x system-on-chip, also known 704 as R-8610-(G). 705 If you don't have one of these chips, you should say N here. 706 707config X86_32_NON_STANDARD 708 bool "Support non-standard 32-bit SMP architectures" 709 depends on X86_32 && SMP 710 depends on X86_EXTENDED_PLATFORM 711 help 712 This option compiles in the bigsmp and STA2X11 default 713 subarchitectures. It is intended for a generic binary 714 kernel. If you select them all, kernel will probe it one by 715 one and will fallback to default. 716 717# Alphabetically sorted list of Non standard 32 bit platforms 718 719config X86_SUPPORTS_MEMORY_FAILURE 720 def_bool y 721 # MCE code calls memory_failure(): 722 depends on X86_MCE 723 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 724 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 725 depends on X86_64 || !SPARSEMEM 726 select ARCH_SUPPORTS_MEMORY_FAILURE 727 728config STA2X11 729 bool "STA2X11 Companion Chip Support" 730 depends on X86_32_NON_STANDARD && PCI 731 select SWIOTLB 732 select MFD_STA2X11 733 select GPIOLIB 734 help 735 This adds support for boards based on the STA2X11 IO-Hub, 736 a.k.a. "ConneXt". The chip is used in place of the standard 737 PC chipset, so all "standard" peripherals are missing. If this 738 option is selected the kernel will still be able to boot on 739 standard PC machines. 740 741config X86_32_IRIS 742 tristate "Eurobraille/Iris poweroff module" 743 depends on X86_32 744 help 745 The Iris machines from EuroBraille do not have APM or ACPI support 746 to shut themselves down properly. A special I/O sequence is 747 needed to do so, which is what this module does at 748 kernel shutdown. 749 750 This is only for Iris machines from EuroBraille. 751 752 If unused, say N. 753 754config SCHED_OMIT_FRAME_POINTER 755 def_bool y 756 prompt "Single-depth WCHAN output" 757 depends on X86 758 help 759 Calculate simpler /proc/<PID>/wchan values. If this option 760 is disabled then wchan values will recurse back to the 761 caller function. This provides more accurate wchan values, 762 at the expense of slightly more scheduling overhead. 763 764 If in doubt, say "Y". 765 766menuconfig HYPERVISOR_GUEST 767 bool "Linux guest support" 768 help 769 Say Y here to enable options for running Linux under various hyper- 770 visors. This option enables basic hypervisor detection and platform 771 setup. 772 773 If you say N, all options in this submenu will be skipped and 774 disabled, and Linux guest support won't be built in. 775 776if HYPERVISOR_GUEST 777 778config PARAVIRT 779 bool "Enable paravirtualization code" 780 help 781 This changes the kernel so it can modify itself when it is run 782 under a hypervisor, potentially improving performance significantly 783 over full virtualization. However, when run without a hypervisor 784 the kernel is theoretically slower and slightly larger. 785 786config PARAVIRT_XXL 787 bool 788 789config PARAVIRT_DEBUG 790 bool "paravirt-ops debugging" 791 depends on PARAVIRT && DEBUG_KERNEL 792 help 793 Enable to debug paravirt_ops internals. Specifically, BUG if 794 a paravirt_op is missing when it is called. 795 796config PARAVIRT_SPINLOCKS 797 bool "Paravirtualization layer for spinlocks" 798 depends on PARAVIRT && SMP 799 help 800 Paravirtualized spinlocks allow a pvops backend to replace the 801 spinlock implementation with something virtualization-friendly 802 (for example, block the virtual CPU rather than spinning). 803 804 It has a minimal impact on native kernels and gives a nice performance 805 benefit on paravirtualized KVM / Xen kernels. 806 807 If you are unsure how to answer this question, answer Y. 808 809config X86_HV_CALLBACK_VECTOR 810 def_bool n 811 812source "arch/x86/xen/Kconfig" 813 814config KVM_GUEST 815 bool "KVM Guest support (including kvmclock)" 816 depends on PARAVIRT 817 select PARAVIRT_CLOCK 818 select ARCH_CPUIDLE_HALTPOLL 819 select X86_HV_CALLBACK_VECTOR 820 default y 821 help 822 This option enables various optimizations for running under the KVM 823 hypervisor. It includes a paravirtualized clock, so that instead 824 of relying on a PIT (or probably other) emulation by the 825 underlying device model, the host provides the guest with 826 timing infrastructure such as time of day, and system time 827 828config ARCH_CPUIDLE_HALTPOLL 829 def_bool n 830 prompt "Disable host haltpoll when loading haltpoll driver" 831 help 832 If virtualized under KVM, disable host haltpoll. 833 834config PVH 835 bool "Support for running PVH guests" 836 help 837 This option enables the PVH entry point for guest virtual machines 838 as specified in the x86/HVM direct boot ABI. 839 840config PARAVIRT_TIME_ACCOUNTING 841 bool "Paravirtual steal time accounting" 842 depends on PARAVIRT 843 help 844 Select this option to enable fine granularity task steal time 845 accounting. Time spent executing other tasks in parallel with 846 the current vCPU is discounted from the vCPU power. To account for 847 that, there can be a small performance impact. 848 849 If in doubt, say N here. 850 851config PARAVIRT_CLOCK 852 bool 853 854config JAILHOUSE_GUEST 855 bool "Jailhouse non-root cell support" 856 depends on X86_64 && PCI 857 select X86_PM_TIMER 858 help 859 This option allows to run Linux as guest in a Jailhouse non-root 860 cell. You can leave this option disabled if you only want to start 861 Jailhouse and run Linux afterwards in the root cell. 862 863config ACRN_GUEST 864 bool "ACRN Guest support" 865 depends on X86_64 866 select X86_HV_CALLBACK_VECTOR 867 help 868 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is 869 a flexible, lightweight reference open-source hypervisor, built with 870 real-time and safety-criticality in mind. It is built for embedded 871 IOT with small footprint and real-time features. More details can be 872 found in https://projectacrn.org/. 873 874endif #HYPERVISOR_GUEST 875 876source "arch/x86/Kconfig.cpu" 877 878config HPET_TIMER 879 def_bool X86_64 880 prompt "HPET Timer Support" if X86_32 881 help 882 Use the IA-PC HPET (High Precision Event Timer) to manage 883 time in preference to the PIT and RTC, if a HPET is 884 present. 885 HPET is the next generation timer replacing legacy 8254s. 886 The HPET provides a stable time base on SMP 887 systems, unlike the TSC, but it is more expensive to access, 888 as it is off-chip. The interface used is documented 889 in the HPET spec, revision 1. 890 891 You can safely choose Y here. However, HPET will only be 892 activated if the platform and the BIOS support this feature. 893 Otherwise the 8254 will be used for timing services. 894 895 Choose N to continue using the legacy 8254 timer. 896 897config HPET_EMULATE_RTC 898 def_bool y 899 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 900 901# Mark as expert because too many people got it wrong. 902# The code disables itself when not needed. 903config DMI 904 default y 905 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK 906 bool "Enable DMI scanning" if EXPERT 907 help 908 Enabled scanning of DMI to identify machine quirks. Say Y 909 here unless you have verified that your setup is not 910 affected by entries in the DMI blacklist. Required by PNP 911 BIOS code. 912 913config GART_IOMMU 914 bool "Old AMD GART IOMMU support" 915 select DMA_OPS 916 select IOMMU_HELPER 917 select SWIOTLB 918 depends on X86_64 && PCI && AMD_NB 919 help 920 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron 921 GART based hardware IOMMUs. 922 923 The GART supports full DMA access for devices with 32-bit access 924 limitations, on systems with more than 3 GB. This is usually needed 925 for USB, sound, many IDE/SATA chipsets and some other devices. 926 927 Newer systems typically have a modern AMD IOMMU, supported via 928 the CONFIG_AMD_IOMMU=y config option. 929 930 In normal configurations this driver is only active when needed: 931 there's more than 3 GB of memory and the system contains a 932 32-bit limited device. 933 934 If unsure, say Y. 935 936config MAXSMP 937 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 938 depends on X86_64 && SMP && DEBUG_KERNEL 939 select CPUMASK_OFFSTACK 940 help 941 Enable maximum number of CPUS and NUMA Nodes for this architecture. 942 If unsure, say N. 943 944# 945# The maximum number of CPUs supported: 946# 947# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, 948# and which can be configured interactively in the 949# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. 950# 951# The ranges are different on 32-bit and 64-bit kernels, depending on 952# hardware capabilities and scalability features of the kernel. 953# 954# ( If MAXSMP is enabled we just use the highest possible value and disable 955# interactive configuration. ) 956# 957 958config NR_CPUS_RANGE_BEGIN 959 int 960 default NR_CPUS_RANGE_END if MAXSMP 961 default 1 if !SMP 962 default 2 963 964config NR_CPUS_RANGE_END 965 int 966 depends on X86_32 967 default 64 if SMP && X86_BIGSMP 968 default 8 if SMP && !X86_BIGSMP 969 default 1 if !SMP 970 971config NR_CPUS_RANGE_END 972 int 973 depends on X86_64 974 default 8192 if SMP && CPUMASK_OFFSTACK 975 default 512 if SMP && !CPUMASK_OFFSTACK 976 default 1 if !SMP 977 978config NR_CPUS_DEFAULT 979 int 980 depends on X86_32 981 default 32 if X86_BIGSMP 982 default 8 if SMP 983 default 1 if !SMP 984 985config NR_CPUS_DEFAULT 986 int 987 depends on X86_64 988 default 8192 if MAXSMP 989 default 64 if SMP 990 default 1 if !SMP 991 992config NR_CPUS 993 int "Maximum number of CPUs" if SMP && !MAXSMP 994 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END 995 default NR_CPUS_DEFAULT 996 help 997 This allows you to specify the maximum number of CPUs which this 998 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum 999 supported value is 8192, otherwise the maximum value is 512. The 1000 minimum value which makes sense is 2. 1001 1002 This is purely to save memory: each supported CPU adds about 8KB 1003 to the kernel image. 1004 1005config SCHED_SMT 1006 def_bool y if SMP 1007 1008config SCHED_MC 1009 def_bool y 1010 prompt "Multi-core scheduler support" 1011 depends on SMP 1012 help 1013 Multi-core scheduler support improves the CPU scheduler's decision 1014 making when dealing with multi-core CPU chips at a cost of slightly 1015 increased overhead in some places. If unsure say N here. 1016 1017config SCHED_MC_PRIO 1018 bool "CPU core priorities scheduler support" 1019 depends on SCHED_MC && CPU_SUP_INTEL 1020 select X86_INTEL_PSTATE 1021 select CPU_FREQ 1022 default y 1023 help 1024 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a 1025 core ordering determined at manufacturing time, which allows 1026 certain cores to reach higher turbo frequencies (when running 1027 single threaded workloads) than others. 1028 1029 Enabling this kernel feature teaches the scheduler about 1030 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the 1031 scheduler's CPU selection logic accordingly, so that higher 1032 overall system performance can be achieved. 1033 1034 This feature will have no effect on CPUs without this feature. 1035 1036 If unsure say Y here. 1037 1038config UP_LATE_INIT 1039 def_bool y 1040 depends on !SMP && X86_LOCAL_APIC 1041 1042config X86_UP_APIC 1043 bool "Local APIC support on uniprocessors" if !PCI_MSI 1044 default PCI_MSI 1045 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 1046 help 1047 A local APIC (Advanced Programmable Interrupt Controller) is an 1048 integrated interrupt controller in the CPU. If you have a single-CPU 1049 system which has a processor with a local APIC, you can say Y here to 1050 enable and use it. If you say Y here even though your machine doesn't 1051 have a local APIC, then the kernel will still run with no slowdown at 1052 all. The local APIC supports CPU-generated self-interrupts (timer, 1053 performance counters), and the NMI watchdog which detects hard 1054 lockups. 1055 1056config X86_UP_IOAPIC 1057 bool "IO-APIC support on uniprocessors" 1058 depends on X86_UP_APIC 1059 help 1060 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 1061 SMP-capable replacement for PC-style interrupt controllers. Most 1062 SMP systems and many recent uniprocessor systems have one. 1063 1064 If you have a single-CPU system with an IO-APIC, you can say Y here 1065 to use it. If you say Y here even though your machine doesn't have 1066 an IO-APIC, then the kernel will still run with no slowdown at all. 1067 1068config X86_LOCAL_APIC 1069 def_bool y 1070 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 1071 select IRQ_DOMAIN_HIERARCHY 1072 select PCI_MSI_IRQ_DOMAIN if PCI_MSI 1073 1074config X86_IO_APIC 1075 def_bool y 1076 depends on X86_LOCAL_APIC || X86_UP_IOAPIC 1077 1078config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 1079 bool "Reroute for broken boot IRQs" 1080 depends on X86_IO_APIC 1081 help 1082 This option enables a workaround that fixes a source of 1083 spurious interrupts. This is recommended when threaded 1084 interrupt handling is used on systems where the generation of 1085 superfluous "boot interrupts" cannot be disabled. 1086 1087 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 1088 entry in the chipset's IO-APIC is masked (as, e.g. the RT 1089 kernel does during interrupt handling). On chipsets where this 1090 boot IRQ generation cannot be disabled, this workaround keeps 1091 the original IRQ line masked so that only the equivalent "boot 1092 IRQ" is delivered to the CPUs. The workaround also tells the 1093 kernel to set up the IRQ handler on the boot IRQ line. In this 1094 way only one interrupt is delivered to the kernel. Otherwise 1095 the spurious second interrupt may cause the kernel to bring 1096 down (vital) interrupt lines. 1097 1098 Only affects "broken" chipsets. Interrupt sharing may be 1099 increased on these systems. 1100 1101config X86_MCE 1102 bool "Machine Check / overheating reporting" 1103 select GENERIC_ALLOCATOR 1104 default y 1105 help 1106 Machine Check support allows the processor to notify the 1107 kernel if it detects a problem (e.g. overheating, data corruption). 1108 The action the kernel takes depends on the severity of the problem, 1109 ranging from warning messages to halting the machine. 1110 1111config X86_MCELOG_LEGACY 1112 bool "Support for deprecated /dev/mcelog character device" 1113 depends on X86_MCE 1114 help 1115 Enable support for /dev/mcelog which is needed by the old mcelog 1116 userspace logging daemon. Consider switching to the new generation 1117 rasdaemon solution. 1118 1119config X86_MCE_INTEL 1120 def_bool y 1121 prompt "Intel MCE features" 1122 depends on X86_MCE && X86_LOCAL_APIC 1123 help 1124 Additional support for intel specific MCE features such as 1125 the thermal monitor. 1126 1127config X86_MCE_AMD 1128 def_bool y 1129 prompt "AMD MCE features" 1130 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB 1131 help 1132 Additional support for AMD specific MCE features such as 1133 the DRAM Error Threshold. 1134 1135config X86_ANCIENT_MCE 1136 bool "Support for old Pentium 5 / WinChip machine checks" 1137 depends on X86_32 && X86_MCE 1138 help 1139 Include support for machine check handling on old Pentium 5 or WinChip 1140 systems. These typically need to be enabled explicitly on the command 1141 line. 1142 1143config X86_MCE_THRESHOLD 1144 depends on X86_MCE_AMD || X86_MCE_INTEL 1145 def_bool y 1146 1147config X86_MCE_INJECT 1148 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS 1149 tristate "Machine check injector support" 1150 help 1151 Provide support for injecting machine checks for testing purposes. 1152 If you don't know what a machine check is and you don't do kernel 1153 QA it is safe to say n. 1154 1155source "arch/x86/events/Kconfig" 1156 1157config X86_LEGACY_VM86 1158 bool "Legacy VM86 support" 1159 depends on X86_32 1160 help 1161 This option allows user programs to put the CPU into V8086 1162 mode, which is an 80286-era approximation of 16-bit real mode. 1163 1164 Some very old versions of X and/or vbetool require this option 1165 for user mode setting. Similarly, DOSEMU will use it if 1166 available to accelerate real mode DOS programs. However, any 1167 recent version of DOSEMU, X, or vbetool should be fully 1168 functional even without kernel VM86 support, as they will all 1169 fall back to software emulation. Nevertheless, if you are using 1170 a 16-bit DOS program where 16-bit performance matters, vm86 1171 mode might be faster than emulation and you might want to 1172 enable this option. 1173 1174 Note that any app that works on a 64-bit kernel is unlikely to 1175 need this option, as 64-bit kernels don't, and can't, support 1176 V8086 mode. This option is also unrelated to 16-bit protected 1177 mode and is not needed to run most 16-bit programs under Wine. 1178 1179 Enabling this option increases the complexity of the kernel 1180 and slows down exception handling a tiny bit. 1181 1182 If unsure, say N here. 1183 1184config VM86 1185 bool 1186 default X86_LEGACY_VM86 1187 1188config X86_16BIT 1189 bool "Enable support for 16-bit segments" if EXPERT 1190 default y 1191 depends on MODIFY_LDT_SYSCALL 1192 help 1193 This option is required by programs like Wine to run 16-bit 1194 protected mode legacy code on x86 processors. Disabling 1195 this option saves about 300 bytes on i386, or around 6K text 1196 plus 16K runtime memory on x86-64, 1197 1198config X86_ESPFIX32 1199 def_bool y 1200 depends on X86_16BIT && X86_32 1201 1202config X86_ESPFIX64 1203 def_bool y 1204 depends on X86_16BIT && X86_64 1205 1206config X86_VSYSCALL_EMULATION 1207 bool "Enable vsyscall emulation" if EXPERT 1208 default y 1209 depends on X86_64 1210 help 1211 This enables emulation of the legacy vsyscall page. Disabling 1212 it is roughly equivalent to booting with vsyscall=none, except 1213 that it will also disable the helpful warning if a program 1214 tries to use a vsyscall. With this option set to N, offending 1215 programs will just segfault, citing addresses of the form 1216 0xffffffffff600?00. 1217 1218 This option is required by many programs built before 2013, and 1219 care should be used even with newer programs if set to N. 1220 1221 Disabling this option saves about 7K of kernel size and 1222 possibly 4K of additional runtime pagetable memory. 1223 1224config X86_IOPL_IOPERM 1225 bool "IOPERM and IOPL Emulation" 1226 default y 1227 help 1228 This enables the ioperm() and iopl() syscalls which are necessary 1229 for legacy applications. 1230 1231 Legacy IOPL support is an overbroad mechanism which allows user 1232 space aside of accessing all 65536 I/O ports also to disable 1233 interrupts. To gain this access the caller needs CAP_SYS_RAWIO 1234 capabilities and permission from potentially active security 1235 modules. 1236 1237 The emulation restricts the functionality of the syscall to 1238 only allowing the full range I/O port access, but prevents the 1239 ability to disable interrupts from user space which would be 1240 granted if the hardware IOPL mechanism would be used. 1241 1242config TOSHIBA 1243 tristate "Toshiba Laptop support" 1244 depends on X86_32 1245 help 1246 This adds a driver to safely access the System Management Mode of 1247 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 1248 not work on models with a Phoenix BIOS. The System Management Mode 1249 is used to set the BIOS and power saving options on Toshiba portables. 1250 1251 For information on utilities to make use of this driver see the 1252 Toshiba Linux utilities web site at: 1253 <http://www.buzzard.org.uk/toshiba/>. 1254 1255 Say Y if you intend to run this kernel on a Toshiba portable. 1256 Say N otherwise. 1257 1258config I8K 1259 tristate "Dell i8k legacy laptop support" 1260 select HWMON 1261 select SENSORS_DELL_SMM 1262 help 1263 This option enables legacy /proc/i8k userspace interface in hwmon 1264 dell-smm-hwmon driver. Character file /proc/i8k reports bios version, 1265 temperature and allows controlling fan speeds of Dell laptops via 1266 System Management Mode. For old Dell laptops (like Dell Inspiron 8000) 1267 it reports also power and hotkey status. For fan speed control is 1268 needed userspace package i8kutils. 1269 1270 Say Y if you intend to run this kernel on old Dell laptops or want to 1271 use userspace package i8kutils. 1272 Say N otherwise. 1273 1274config X86_REBOOTFIXUPS 1275 bool "Enable X86 board specific fixups for reboot" 1276 depends on X86_32 1277 help 1278 This enables chipset and/or board specific fixups to be done 1279 in order to get reboot to work correctly. This is only needed on 1280 some combinations of hardware and BIOS. The symptom, for which 1281 this config is intended, is when reboot ends with a stalled/hung 1282 system. 1283 1284 Currently, the only fixup is for the Geode machines using 1285 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1286 1287 Say Y if you want to enable the fixup. Currently, it's safe to 1288 enable this option even if you don't need it. 1289 Say N otherwise. 1290 1291config MICROCODE 1292 bool "CPU microcode loading support" 1293 default y 1294 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1295 help 1296 If you say Y here, you will be able to update the microcode on 1297 Intel and AMD processors. The Intel support is for the IA32 family, 1298 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The 1299 AMD support is for families 0x10 and later. You will obviously need 1300 the actual microcode binary data itself which is not shipped with 1301 the Linux kernel. 1302 1303 The preferred method to load microcode from a detached initrd is described 1304 in Documentation/x86/microcode.rst. For that you need to enable 1305 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the 1306 initrd for microcode blobs. 1307 1308 In addition, you can build the microcode into the kernel. For that you 1309 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE 1310 config option. 1311 1312config MICROCODE_INTEL 1313 bool "Intel microcode loading support" 1314 depends on MICROCODE 1315 default MICROCODE 1316 help 1317 This options enables microcode patch loading support for Intel 1318 processors. 1319 1320 For the current Intel microcode data package go to 1321 <https://downloadcenter.intel.com> and search for 1322 'Linux Processor Microcode Data File'. 1323 1324config MICROCODE_AMD 1325 bool "AMD microcode loading support" 1326 depends on MICROCODE 1327 help 1328 If you select this option, microcode patch loading support for AMD 1329 processors will be enabled. 1330 1331config MICROCODE_OLD_INTERFACE 1332 bool "Ancient loading interface (DEPRECATED)" 1333 default n 1334 depends on MICROCODE 1335 help 1336 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface 1337 which was used by userspace tools like iucode_tool and microcode.ctl. 1338 It is inadequate because it runs too late to be able to properly 1339 load microcode on a machine and it needs special tools. Instead, you 1340 should've switched to the early loading method with the initrd or 1341 builtin microcode by now: Documentation/x86/microcode.rst 1342 1343config X86_MSR 1344 tristate "/dev/cpu/*/msr - Model-specific register support" 1345 help 1346 This device gives privileged processes access to the x86 1347 Model-Specific Registers (MSRs). It is a character device with 1348 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1349 MSR accesses are directed to a specific CPU on multi-processor 1350 systems. 1351 1352config X86_CPUID 1353 tristate "/dev/cpu/*/cpuid - CPU information support" 1354 help 1355 This device gives processes access to the x86 CPUID instruction to 1356 be executed on a specific processor. It is a character device 1357 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1358 /dev/cpu/31/cpuid. 1359 1360choice 1361 prompt "High Memory Support" 1362 default HIGHMEM4G 1363 depends on X86_32 1364 1365config NOHIGHMEM 1366 bool "off" 1367 help 1368 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1369 However, the address space of 32-bit x86 processors is only 4 1370 Gigabytes large. That means that, if you have a large amount of 1371 physical memory, not all of it can be "permanently mapped" by the 1372 kernel. The physical memory that's not permanently mapped is called 1373 "high memory". 1374 1375 If you are compiling a kernel which will never run on a machine with 1376 more than 1 Gigabyte total physical RAM, answer "off" here (default 1377 choice and suitable for most users). This will result in a "3GB/1GB" 1378 split: 3GB are mapped so that each process sees a 3GB virtual memory 1379 space and the remaining part of the 4GB virtual memory space is used 1380 by the kernel to permanently map as much physical memory as 1381 possible. 1382 1383 If the machine has between 1 and 4 Gigabytes physical RAM, then 1384 answer "4GB" here. 1385 1386 If more than 4 Gigabytes is used then answer "64GB" here. This 1387 selection turns Intel PAE (Physical Address Extension) mode on. 1388 PAE implements 3-level paging on IA32 processors. PAE is fully 1389 supported by Linux, PAE mode is implemented on all recent Intel 1390 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1391 then the kernel will not boot on CPUs that don't support PAE! 1392 1393 The actual amount of total physical memory will either be 1394 auto detected or can be forced by using a kernel command line option 1395 such as "mem=256M". (Try "man bootparam" or see the documentation of 1396 your boot loader (lilo or loadlin) about how to pass options to the 1397 kernel at boot time.) 1398 1399 If unsure, say "off". 1400 1401config HIGHMEM4G 1402 bool "4GB" 1403 help 1404 Select this if you have a 32-bit processor and between 1 and 4 1405 gigabytes of physical RAM. 1406 1407config HIGHMEM64G 1408 bool "64GB" 1409 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 1410 select X86_PAE 1411 help 1412 Select this if you have a 32-bit processor and more than 4 1413 gigabytes of physical RAM. 1414 1415endchoice 1416 1417choice 1418 prompt "Memory split" if EXPERT 1419 default VMSPLIT_3G 1420 depends on X86_32 1421 help 1422 Select the desired split between kernel and user memory. 1423 1424 If the address range available to the kernel is less than the 1425 physical memory installed, the remaining memory will be available 1426 as "high memory". Accessing high memory is a little more costly 1427 than low memory, as it needs to be mapped into the kernel first. 1428 Note that increasing the kernel address space limits the range 1429 available to user programs, making the address space there 1430 tighter. Selecting anything other than the default 3G/1G split 1431 will also likely make your kernel incompatible with binary-only 1432 kernel modules. 1433 1434 If you are not absolutely sure what you are doing, leave this 1435 option alone! 1436 1437 config VMSPLIT_3G 1438 bool "3G/1G user/kernel split" 1439 config VMSPLIT_3G_OPT 1440 depends on !X86_PAE 1441 bool "3G/1G user/kernel split (for full 1G low memory)" 1442 config VMSPLIT_2G 1443 bool "2G/2G user/kernel split" 1444 config VMSPLIT_2G_OPT 1445 depends on !X86_PAE 1446 bool "2G/2G user/kernel split (for full 2G low memory)" 1447 config VMSPLIT_1G 1448 bool "1G/3G user/kernel split" 1449endchoice 1450 1451config PAGE_OFFSET 1452 hex 1453 default 0xB0000000 if VMSPLIT_3G_OPT 1454 default 0x80000000 if VMSPLIT_2G 1455 default 0x78000000 if VMSPLIT_2G_OPT 1456 default 0x40000000 if VMSPLIT_1G 1457 default 0xC0000000 1458 depends on X86_32 1459 1460config HIGHMEM 1461 def_bool y 1462 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1463 1464config X86_PAE 1465 bool "PAE (Physical Address Extension) Support" 1466 depends on X86_32 && !HIGHMEM4G 1467 select PHYS_ADDR_T_64BIT 1468 select SWIOTLB 1469 help 1470 PAE is required for NX support, and furthermore enables 1471 larger swapspace support for non-overcommit purposes. It 1472 has the cost of more pagetable lookup overhead, and also 1473 consumes more pagetable space per process. 1474 1475config X86_5LEVEL 1476 bool "Enable 5-level page tables support" 1477 default y 1478 select DYNAMIC_MEMORY_LAYOUT 1479 select SPARSEMEM_VMEMMAP 1480 depends on X86_64 1481 help 1482 5-level paging enables access to larger address space: 1483 upto 128 PiB of virtual address space and 4 PiB of 1484 physical address space. 1485 1486 It will be supported by future Intel CPUs. 1487 1488 A kernel with the option enabled can be booted on machines that 1489 support 4- or 5-level paging. 1490 1491 See Documentation/x86/x86_64/5level-paging.rst for more 1492 information. 1493 1494 Say N if unsure. 1495 1496config X86_DIRECT_GBPAGES 1497 def_bool y 1498 depends on X86_64 1499 help 1500 Certain kernel features effectively disable kernel 1501 linear 1 GB mappings (even if the CPU otherwise 1502 supports them), so don't confuse the user by printing 1503 that we have them enabled. 1504 1505config X86_CPA_STATISTICS 1506 bool "Enable statistic for Change Page Attribute" 1507 depends on DEBUG_FS 1508 help 1509 Expose statistics about the Change Page Attribute mechanism, which 1510 helps to determine the effectiveness of preserving large and huge 1511 page mappings when mapping protections are changed. 1512 1513config AMD_MEM_ENCRYPT 1514 bool "AMD Secure Memory Encryption (SME) support" 1515 depends on X86_64 && CPU_SUP_AMD 1516 select DMA_COHERENT_POOL 1517 select DYNAMIC_PHYSICAL_MASK 1518 select ARCH_USE_MEMREMAP_PROT 1519 select ARCH_HAS_FORCE_DMA_UNENCRYPTED 1520 select INSTRUCTION_DECODER 1521 help 1522 Say yes to enable support for the encryption of system memory. 1523 This requires an AMD processor that supports Secure Memory 1524 Encryption (SME). 1525 1526config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT 1527 bool "Activate AMD Secure Memory Encryption (SME) by default" 1528 default y 1529 depends on AMD_MEM_ENCRYPT 1530 help 1531 Say yes to have system memory encrypted by default if running on 1532 an AMD processor that supports Secure Memory Encryption (SME). 1533 1534 If set to Y, then the encryption of system memory can be 1535 deactivated with the mem_encrypt=off command line option. 1536 1537 If set to N, then the encryption of system memory can be 1538 activated with the mem_encrypt=on command line option. 1539 1540# Common NUMA Features 1541config NUMA 1542 bool "NUMA Memory Allocation and Scheduler Support" 1543 depends on SMP 1544 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) 1545 default y if X86_BIGSMP 1546 help 1547 Enable NUMA (Non-Uniform Memory Access) support. 1548 1549 The kernel will try to allocate memory used by a CPU on the 1550 local memory controller of the CPU and add some more 1551 NUMA awareness to the kernel. 1552 1553 For 64-bit this is recommended if the system is Intel Core i7 1554 (or later), AMD Opteron, or EM64T NUMA. 1555 1556 For 32-bit this is only needed if you boot a 32-bit 1557 kernel on a 64-bit NUMA platform. 1558 1559 Otherwise, you should say N. 1560 1561config AMD_NUMA 1562 def_bool y 1563 prompt "Old style AMD Opteron NUMA detection" 1564 depends on X86_64 && NUMA && PCI 1565 help 1566 Enable AMD NUMA node topology detection. You should say Y here if 1567 you have a multi processor AMD system. This uses an old method to 1568 read the NUMA configuration directly from the builtin Northbridge 1569 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1570 which also takes priority if both are compiled in. 1571 1572config X86_64_ACPI_NUMA 1573 def_bool y 1574 prompt "ACPI NUMA detection" 1575 depends on X86_64 && NUMA && ACPI && PCI 1576 select ACPI_NUMA 1577 help 1578 Enable ACPI SRAT based node topology detection. 1579 1580config NUMA_EMU 1581 bool "NUMA emulation" 1582 depends on NUMA 1583 help 1584 Enable NUMA emulation. A flat machine will be split 1585 into virtual nodes when booted with "numa=fake=N", where N is the 1586 number of nodes. This is only useful for debugging. 1587 1588config NODES_SHIFT 1589 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1590 range 1 10 1591 default "10" if MAXSMP 1592 default "6" if X86_64 1593 default "3" 1594 depends on NEED_MULTIPLE_NODES 1595 help 1596 Specify the maximum number of NUMA Nodes available on the target 1597 system. Increases memory reserved to accommodate various tables. 1598 1599config ARCH_FLATMEM_ENABLE 1600 def_bool y 1601 depends on X86_32 && !NUMA 1602 1603config ARCH_SPARSEMEM_ENABLE 1604 def_bool y 1605 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1606 select SPARSEMEM_STATIC if X86_32 1607 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1608 1609config ARCH_SPARSEMEM_DEFAULT 1610 def_bool X86_64 || (NUMA && X86_32) 1611 1612config ARCH_SELECT_MEMORY_MODEL 1613 def_bool y 1614 depends on ARCH_SPARSEMEM_ENABLE 1615 1616config ARCH_MEMORY_PROBE 1617 bool "Enable sysfs memory/probe interface" 1618 depends on X86_64 && MEMORY_HOTPLUG 1619 help 1620 This option enables a sysfs memory/probe interface for testing. 1621 See Documentation/admin-guide/mm/memory-hotplug.rst for more information. 1622 If you are unsure how to answer this question, answer N. 1623 1624config ARCH_PROC_KCORE_TEXT 1625 def_bool y 1626 depends on X86_64 && PROC_KCORE 1627 1628config ILLEGAL_POINTER_VALUE 1629 hex 1630 default 0 if X86_32 1631 default 0xdead000000000000 if X86_64 1632 1633config X86_PMEM_LEGACY_DEVICE 1634 bool 1635 1636config X86_PMEM_LEGACY 1637 tristate "Support non-standard NVDIMMs and ADR protected memory" 1638 depends on PHYS_ADDR_T_64BIT 1639 depends on BLK_DEV 1640 select X86_PMEM_LEGACY_DEVICE 1641 select NUMA_KEEP_MEMINFO if NUMA 1642 select LIBNVDIMM 1643 help 1644 Treat memory marked using the non-standard e820 type of 12 as used 1645 by the Intel Sandy Bridge-EP reference BIOS as protected memory. 1646 The kernel will offer these regions to the 'pmem' driver so 1647 they can be used for persistent storage. 1648 1649 Say Y if unsure. 1650 1651config HIGHPTE 1652 bool "Allocate 3rd-level pagetables from highmem" 1653 depends on HIGHMEM 1654 help 1655 The VM uses one page table entry for each page of physical memory. 1656 For systems with a lot of RAM, this can be wasteful of precious 1657 low memory. Setting this option will put user-space page table 1658 entries in high memory. 1659 1660config X86_CHECK_BIOS_CORRUPTION 1661 bool "Check for low memory corruption" 1662 help 1663 Periodically check for memory corruption in low memory, which 1664 is suspected to be caused by BIOS. Even when enabled in the 1665 configuration, it is disabled at runtime. Enable it by 1666 setting "memory_corruption_check=1" on the kernel command 1667 line. By default it scans the low 64k of memory every 60 1668 seconds; see the memory_corruption_check_size and 1669 memory_corruption_check_period parameters in 1670 Documentation/admin-guide/kernel-parameters.rst to adjust this. 1671 1672 When enabled with the default parameters, this option has 1673 almost no overhead, as it reserves a relatively small amount 1674 of memory and scans it infrequently. It both detects corruption 1675 and prevents it from affecting the running system. 1676 1677 It is, however, intended as a diagnostic tool; if repeatable 1678 BIOS-originated corruption always affects the same memory, 1679 you can use memmap= to prevent the kernel from using that 1680 memory. 1681 1682config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1683 bool "Set the default setting of memory_corruption_check" 1684 depends on X86_CHECK_BIOS_CORRUPTION 1685 default y 1686 help 1687 Set whether the default state of memory_corruption_check is 1688 on or off. 1689 1690config X86_RESERVE_LOW 1691 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1692 default 64 1693 range 4 640 1694 help 1695 Specify the amount of low memory to reserve for the BIOS. 1696 1697 The first page contains BIOS data structures that the kernel 1698 must not use, so that page must always be reserved. 1699 1700 By default we reserve the first 64K of physical RAM, as a 1701 number of BIOSes are known to corrupt that memory range 1702 during events such as suspend/resume or monitor cable 1703 insertion, so it must not be used by the kernel. 1704 1705 You can set this to 4 if you are absolutely sure that you 1706 trust the BIOS to get all its memory reservations and usages 1707 right. If you know your BIOS have problems beyond the 1708 default 64K area, you can set this to 640 to avoid using the 1709 entire low memory range. 1710 1711 If you have doubts about the BIOS (e.g. suspend/resume does 1712 not work or there's kernel crashes after certain hardware 1713 hotplug events) then you might want to enable 1714 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1715 typical corruption patterns. 1716 1717 Leave this to the default value of 64 if you are unsure. 1718 1719config MATH_EMULATION 1720 bool 1721 depends on MODIFY_LDT_SYSCALL 1722 prompt "Math emulation" if X86_32 && (M486SX || MELAN) 1723 help 1724 Linux can emulate a math coprocessor (used for floating point 1725 operations) if you don't have one. 486DX and Pentium processors have 1726 a math coprocessor built in, 486SX and 386 do not, unless you added 1727 a 487DX or 387, respectively. (The messages during boot time can 1728 give you some hints here ["man dmesg"].) Everyone needs either a 1729 coprocessor or this emulation. 1730 1731 If you don't have a math coprocessor, you need to say Y here; if you 1732 say Y here even though you have a coprocessor, the coprocessor will 1733 be used nevertheless. (This behavior can be changed with the kernel 1734 command line option "no387", which comes handy if your coprocessor 1735 is broken. Try "man bootparam" or see the documentation of your boot 1736 loader (lilo or loadlin) about how to pass options to the kernel at 1737 boot time.) This means that it is a good idea to say Y here if you 1738 intend to use this kernel on different machines. 1739 1740 More information about the internals of the Linux math coprocessor 1741 emulation can be found in <file:arch/x86/math-emu/README>. 1742 1743 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1744 kernel, it won't hurt. 1745 1746config MTRR 1747 def_bool y 1748 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1749 help 1750 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1751 the Memory Type Range Registers (MTRRs) may be used to control 1752 processor access to memory ranges. This is most useful if you have 1753 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1754 allows bus write transfers to be combined into a larger transfer 1755 before bursting over the PCI/AGP bus. This can increase performance 1756 of image write operations 2.5 times or more. Saying Y here creates a 1757 /proc/mtrr file which may be used to manipulate your processor's 1758 MTRRs. Typically the X server should use this. 1759 1760 This code has a reasonably generic interface so that similar 1761 control registers on other processors can be easily supported 1762 as well: 1763 1764 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1765 Registers (ARRs) which provide a similar functionality to MTRRs. For 1766 these, the ARRs are used to emulate the MTRRs. 1767 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1768 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1769 write-combining. All of these processors are supported by this code 1770 and it makes sense to say Y here if you have one of them. 1771 1772 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1773 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1774 can lead to all sorts of problems, so it's good to say Y here. 1775 1776 You can safely say Y even if your machine doesn't have MTRRs, you'll 1777 just add about 9 KB to your kernel. 1778 1779 See <file:Documentation/x86/mtrr.rst> for more information. 1780 1781config MTRR_SANITIZER 1782 def_bool y 1783 prompt "MTRR cleanup support" 1784 depends on MTRR 1785 help 1786 Convert MTRR layout from continuous to discrete, so X drivers can 1787 add writeback entries. 1788 1789 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1790 The largest mtrr entry size for a continuous block can be set with 1791 mtrr_chunk_size. 1792 1793 If unsure, say Y. 1794 1795config MTRR_SANITIZER_ENABLE_DEFAULT 1796 int "MTRR cleanup enable value (0-1)" 1797 range 0 1 1798 default "0" 1799 depends on MTRR_SANITIZER 1800 help 1801 Enable mtrr cleanup default value 1802 1803config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1804 int "MTRR cleanup spare reg num (0-7)" 1805 range 0 7 1806 default "1" 1807 depends on MTRR_SANITIZER 1808 help 1809 mtrr cleanup spare entries default, it can be changed via 1810 mtrr_spare_reg_nr=N on the kernel command line. 1811 1812config X86_PAT 1813 def_bool y 1814 prompt "x86 PAT support" if EXPERT 1815 depends on MTRR 1816 help 1817 Use PAT attributes to setup page level cache control. 1818 1819 PATs are the modern equivalents of MTRRs and are much more 1820 flexible than MTRRs. 1821 1822 Say N here if you see bootup problems (boot crash, boot hang, 1823 spontaneous reboots) or a non-working video driver. 1824 1825 If unsure, say Y. 1826 1827config ARCH_USES_PG_UNCACHED 1828 def_bool y 1829 depends on X86_PAT 1830 1831config ARCH_RANDOM 1832 def_bool y 1833 prompt "x86 architectural random number generator" if EXPERT 1834 help 1835 Enable the x86 architectural RDRAND instruction 1836 (Intel Bull Mountain technology) to generate random numbers. 1837 If supported, this is a high bandwidth, cryptographically 1838 secure hardware random number generator. 1839 1840config X86_SMAP 1841 def_bool y 1842 prompt "Supervisor Mode Access Prevention" if EXPERT 1843 help 1844 Supervisor Mode Access Prevention (SMAP) is a security 1845 feature in newer Intel processors. There is a small 1846 performance cost if this enabled and turned on; there is 1847 also a small increase in the kernel size if this is enabled. 1848 1849 If unsure, say Y. 1850 1851config X86_UMIP 1852 def_bool y 1853 prompt "User Mode Instruction Prevention" if EXPERT 1854 help 1855 User Mode Instruction Prevention (UMIP) is a security feature in 1856 some x86 processors. If enabled, a general protection fault is 1857 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are 1858 executed in user mode. These instructions unnecessarily expose 1859 information about the hardware state. 1860 1861 The vast majority of applications do not use these instructions. 1862 For the very few that do, software emulation is provided in 1863 specific cases in protected and virtual-8086 modes. Emulated 1864 results are dummy. 1865 1866config X86_INTEL_MEMORY_PROTECTION_KEYS 1867 prompt "Memory Protection Keys" 1868 def_bool y 1869 # Note: only available in 64-bit mode 1870 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) 1871 select ARCH_USES_HIGH_VMA_FLAGS 1872 select ARCH_HAS_PKEYS 1873 help 1874 Memory Protection Keys provides a mechanism for enforcing 1875 page-based protections, but without requiring modification of the 1876 page tables when an application changes protection domains. 1877 1878 For details, see Documentation/core-api/protection-keys.rst 1879 1880 If unsure, say y. 1881 1882choice 1883 prompt "TSX enable mode" 1884 depends on CPU_SUP_INTEL 1885 default X86_INTEL_TSX_MODE_OFF 1886 help 1887 Intel's TSX (Transactional Synchronization Extensions) feature 1888 allows to optimize locking protocols through lock elision which 1889 can lead to a noticeable performance boost. 1890 1891 On the other hand it has been shown that TSX can be exploited 1892 to form side channel attacks (e.g. TAA) and chances are there 1893 will be more of those attacks discovered in the future. 1894 1895 Therefore TSX is not enabled by default (aka tsx=off). An admin 1896 might override this decision by tsx=on the command line parameter. 1897 Even with TSX enabled, the kernel will attempt to enable the best 1898 possible TAA mitigation setting depending on the microcode available 1899 for the particular machine. 1900 1901 This option allows to set the default tsx mode between tsx=on, =off 1902 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more 1903 details. 1904 1905 Say off if not sure, auto if TSX is in use but it should be used on safe 1906 platforms or on if TSX is in use and the security aspect of tsx is not 1907 relevant. 1908 1909config X86_INTEL_TSX_MODE_OFF 1910 bool "off" 1911 help 1912 TSX is disabled if possible - equals to tsx=off command line parameter. 1913 1914config X86_INTEL_TSX_MODE_ON 1915 bool "on" 1916 help 1917 TSX is always enabled on TSX capable HW - equals the tsx=on command 1918 line parameter. 1919 1920config X86_INTEL_TSX_MODE_AUTO 1921 bool "auto" 1922 help 1923 TSX is enabled on TSX capable HW that is believed to be safe against 1924 side channel attacks- equals the tsx=auto command line parameter. 1925endchoice 1926 1927config X86_SGX 1928 bool "Software Guard eXtensions (SGX)" 1929 depends on X86_64 && CPU_SUP_INTEL 1930 depends on CRYPTO=y 1931 depends on CRYPTO_SHA256=y 1932 select SRCU 1933 select MMU_NOTIFIER 1934 help 1935 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions 1936 that can be used by applications to set aside private regions of code 1937 and data, referred to as enclaves. An enclave's private memory can 1938 only be accessed by code running within the enclave. Accesses from 1939 outside the enclave, including other enclaves, are disallowed by 1940 hardware. 1941 1942 If unsure, say N. 1943 1944config EFI 1945 bool "EFI runtime service support" 1946 depends on ACPI 1947 select UCS2_STRING 1948 select EFI_RUNTIME_WRAPPERS 1949 help 1950 This enables the kernel to use EFI runtime services that are 1951 available (such as the EFI variable services). 1952 1953 This option is only useful on systems that have EFI firmware. 1954 In addition, you should use the latest ELILO loader available 1955 at <http://elilo.sourceforge.net> in order to take advantage 1956 of EFI runtime services. However, even with this option, the 1957 resultant kernel should continue to boot on existing non-EFI 1958 platforms. 1959 1960config EFI_STUB 1961 bool "EFI stub support" 1962 depends on EFI && !X86_USE_3DNOW 1963 depends on $(cc-option,-mabi=ms) || X86_32 1964 select RELOCATABLE 1965 help 1966 This kernel feature allows a bzImage to be loaded directly 1967 by EFI firmware without the use of a bootloader. 1968 1969 See Documentation/admin-guide/efi-stub.rst for more information. 1970 1971config EFI_MIXED 1972 bool "EFI mixed-mode support" 1973 depends on EFI_STUB && X86_64 1974 help 1975 Enabling this feature allows a 64-bit kernel to be booted 1976 on a 32-bit firmware, provided that your CPU supports 64-bit 1977 mode. 1978 1979 Note that it is not possible to boot a mixed-mode enabled 1980 kernel via the EFI boot stub - a bootloader that supports 1981 the EFI handover protocol must be used. 1982 1983 If unsure, say N. 1984 1985source "kernel/Kconfig.hz" 1986 1987config KEXEC 1988 bool "kexec system call" 1989 select KEXEC_CORE 1990 help 1991 kexec is a system call that implements the ability to shutdown your 1992 current kernel, and to start another kernel. It is like a reboot 1993 but it is independent of the system firmware. And like a reboot 1994 you can start any kernel with it, not just Linux. 1995 1996 The name comes from the similarity to the exec system call. 1997 1998 It is an ongoing process to be certain the hardware in a machine 1999 is properly shutdown, so do not be surprised if this code does not 2000 initially work for you. As of this writing the exact hardware 2001 interface is strongly in flux, so no good recommendation can be 2002 made. 2003 2004config KEXEC_FILE 2005 bool "kexec file based system call" 2006 select KEXEC_CORE 2007 select BUILD_BIN2C 2008 depends on X86_64 2009 depends on CRYPTO=y 2010 depends on CRYPTO_SHA256=y 2011 help 2012 This is new version of kexec system call. This system call is 2013 file based and takes file descriptors as system call argument 2014 for kernel and initramfs as opposed to list of segments as 2015 accepted by previous system call. 2016 2017config ARCH_HAS_KEXEC_PURGATORY 2018 def_bool KEXEC_FILE 2019 2020config KEXEC_SIG 2021 bool "Verify kernel signature during kexec_file_load() syscall" 2022 depends on KEXEC_FILE 2023 help 2024 2025 This option makes the kexec_file_load() syscall check for a valid 2026 signature of the kernel image. The image can still be loaded without 2027 a valid signature unless you also enable KEXEC_SIG_FORCE, though if 2028 there's a signature that we can check, then it must be valid. 2029 2030 In addition to this option, you need to enable signature 2031 verification for the corresponding kernel image type being 2032 loaded in order for this to work. 2033 2034config KEXEC_SIG_FORCE 2035 bool "Require a valid signature in kexec_file_load() syscall" 2036 depends on KEXEC_SIG 2037 help 2038 This option makes kernel signature verification mandatory for 2039 the kexec_file_load() syscall. 2040 2041config KEXEC_BZIMAGE_VERIFY_SIG 2042 bool "Enable bzImage signature verification support" 2043 depends on KEXEC_SIG 2044 depends on SIGNED_PE_FILE_VERIFICATION 2045 select SYSTEM_TRUSTED_KEYRING 2046 help 2047 Enable bzImage signature verification support. 2048 2049config CRASH_DUMP 2050 bool "kernel crash dumps" 2051 depends on X86_64 || (X86_32 && HIGHMEM) 2052 help 2053 Generate crash dump after being started by kexec. 2054 This should be normally only set in special crash dump kernels 2055 which are loaded in the main kernel with kexec-tools into 2056 a specially reserved region and then later executed after 2057 a crash by kdump/kexec. The crash dump kernel must be compiled 2058 to a memory address not used by the main kernel or BIOS using 2059 PHYSICAL_START, or it must be built as a relocatable image 2060 (CONFIG_RELOCATABLE=y). 2061 For more details see Documentation/admin-guide/kdump/kdump.rst 2062 2063config KEXEC_JUMP 2064 bool "kexec jump" 2065 depends on KEXEC && HIBERNATION 2066 help 2067 Jump between original kernel and kexeced kernel and invoke 2068 code in physical address mode via KEXEC 2069 2070config PHYSICAL_START 2071 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 2072 default "0x1000000" 2073 help 2074 This gives the physical address where the kernel is loaded. 2075 2076 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 2077 bzImage will decompress itself to above physical address and 2078 run from there. Otherwise, bzImage will run from the address where 2079 it has been loaded by the boot loader and will ignore above physical 2080 address. 2081 2082 In normal kdump cases one does not have to set/change this option 2083 as now bzImage can be compiled as a completely relocatable image 2084 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 2085 address. This option is mainly useful for the folks who don't want 2086 to use a bzImage for capturing the crash dump and want to use a 2087 vmlinux instead. vmlinux is not relocatable hence a kernel needs 2088 to be specifically compiled to run from a specific memory area 2089 (normally a reserved region) and this option comes handy. 2090 2091 So if you are using bzImage for capturing the crash dump, 2092 leave the value here unchanged to 0x1000000 and set 2093 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 2094 for capturing the crash dump change this value to start of 2095 the reserved region. In other words, it can be set based on 2096 the "X" value as specified in the "crashkernel=YM@XM" 2097 command line boot parameter passed to the panic-ed 2098 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst 2099 for more details about crash dumps. 2100 2101 Usage of bzImage for capturing the crash dump is recommended as 2102 one does not have to build two kernels. Same kernel can be used 2103 as production kernel and capture kernel. Above option should have 2104 gone away after relocatable bzImage support is introduced. But it 2105 is present because there are users out there who continue to use 2106 vmlinux for dump capture. This option should go away down the 2107 line. 2108 2109 Don't change this unless you know what you are doing. 2110 2111config RELOCATABLE 2112 bool "Build a relocatable kernel" 2113 default y 2114 help 2115 This builds a kernel image that retains relocation information 2116 so it can be loaded someplace besides the default 1MB. 2117 The relocations tend to make the kernel binary about 10% larger, 2118 but are discarded at runtime. 2119 2120 One use is for the kexec on panic case where the recovery kernel 2121 must live at a different physical address than the primary 2122 kernel. 2123 2124 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 2125 it has been loaded at and the compile time physical address 2126 (CONFIG_PHYSICAL_START) is used as the minimum location. 2127 2128config RANDOMIZE_BASE 2129 bool "Randomize the address of the kernel image (KASLR)" 2130 depends on RELOCATABLE 2131 default y 2132 help 2133 In support of Kernel Address Space Layout Randomization (KASLR), 2134 this randomizes the physical address at which the kernel image 2135 is decompressed and the virtual address where the kernel 2136 image is mapped, as a security feature that deters exploit 2137 attempts relying on knowledge of the location of kernel 2138 code internals. 2139 2140 On 64-bit, the kernel physical and virtual addresses are 2141 randomized separately. The physical address will be anywhere 2142 between 16MB and the top of physical memory (up to 64TB). The 2143 virtual address will be randomized from 16MB up to 1GB (9 bits 2144 of entropy). Note that this also reduces the memory space 2145 available to kernel modules from 1.5GB to 1GB. 2146 2147 On 32-bit, the kernel physical and virtual addresses are 2148 randomized together. They will be randomized from 16MB up to 2149 512MB (8 bits of entropy). 2150 2151 Entropy is generated using the RDRAND instruction if it is 2152 supported. If RDTSC is supported, its value is mixed into 2153 the entropy pool as well. If neither RDRAND nor RDTSC are 2154 supported, then entropy is read from the i8254 timer. The 2155 usable entropy is limited by the kernel being built using 2156 2GB addressing, and that PHYSICAL_ALIGN must be at a 2157 minimum of 2MB. As a result, only 10 bits of entropy are 2158 theoretically possible, but the implementations are further 2159 limited due to memory layouts. 2160 2161 If unsure, say Y. 2162 2163# Relocation on x86 needs some additional build support 2164config X86_NEED_RELOCS 2165 def_bool y 2166 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) 2167 2168config PHYSICAL_ALIGN 2169 hex "Alignment value to which kernel should be aligned" 2170 default "0x200000" 2171 range 0x2000 0x1000000 if X86_32 2172 range 0x200000 0x1000000 if X86_64 2173 help 2174 This value puts the alignment restrictions on physical address 2175 where kernel is loaded and run from. Kernel is compiled for an 2176 address which meets above alignment restriction. 2177 2178 If bootloader loads the kernel at a non-aligned address and 2179 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 2180 address aligned to above value and run from there. 2181 2182 If bootloader loads the kernel at a non-aligned address and 2183 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 2184 load address and decompress itself to the address it has been 2185 compiled for and run from there. The address for which kernel is 2186 compiled already meets above alignment restrictions. Hence the 2187 end result is that kernel runs from a physical address meeting 2188 above alignment restrictions. 2189 2190 On 32-bit this value must be a multiple of 0x2000. On 64-bit 2191 this value must be a multiple of 0x200000. 2192 2193 Don't change this unless you know what you are doing. 2194 2195config DYNAMIC_MEMORY_LAYOUT 2196 bool 2197 help 2198 This option makes base addresses of vmalloc and vmemmap as well as 2199 __PAGE_OFFSET movable during boot. 2200 2201config RANDOMIZE_MEMORY 2202 bool "Randomize the kernel memory sections" 2203 depends on X86_64 2204 depends on RANDOMIZE_BASE 2205 select DYNAMIC_MEMORY_LAYOUT 2206 default RANDOMIZE_BASE 2207 help 2208 Randomizes the base virtual address of kernel memory sections 2209 (physical memory mapping, vmalloc & vmemmap). This security feature 2210 makes exploits relying on predictable memory locations less reliable. 2211 2212 The order of allocations remains unchanged. Entropy is generated in 2213 the same way as RANDOMIZE_BASE. Current implementation in the optimal 2214 configuration have in average 30,000 different possible virtual 2215 addresses for each memory section. 2216 2217 If unsure, say Y. 2218 2219config RANDOMIZE_MEMORY_PHYSICAL_PADDING 2220 hex "Physical memory mapping padding" if EXPERT 2221 depends on RANDOMIZE_MEMORY 2222 default "0xa" if MEMORY_HOTPLUG 2223 default "0x0" 2224 range 0x1 0x40 if MEMORY_HOTPLUG 2225 range 0x0 0x40 2226 help 2227 Define the padding in terabytes added to the existing physical 2228 memory size during kernel memory randomization. It is useful 2229 for memory hotplug support but reduces the entropy available for 2230 address randomization. 2231 2232 If unsure, leave at the default value. 2233 2234config HOTPLUG_CPU 2235 def_bool y 2236 depends on SMP 2237 2238config BOOTPARAM_HOTPLUG_CPU0 2239 bool "Set default setting of cpu0_hotpluggable" 2240 depends on HOTPLUG_CPU 2241 help 2242 Set whether default state of cpu0_hotpluggable is on or off. 2243 2244 Say Y here to enable CPU0 hotplug by default. If this switch 2245 is turned on, there is no need to give cpu0_hotplug kernel 2246 parameter and the CPU0 hotplug feature is enabled by default. 2247 2248 Please note: there are two known CPU0 dependencies if you want 2249 to enable the CPU0 hotplug feature either by this switch or by 2250 cpu0_hotplug kernel parameter. 2251 2252 First, resume from hibernate or suspend always starts from CPU0. 2253 So hibernate and suspend are prevented if CPU0 is offline. 2254 2255 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 2256 offline if any interrupt can not migrate out of CPU0. There may 2257 be other CPU0 dependencies. 2258 2259 Please make sure the dependencies are under your control before 2260 you enable this feature. 2261 2262 Say N if you don't want to enable CPU0 hotplug feature by default. 2263 You still can enable the CPU0 hotplug feature at boot by kernel 2264 parameter cpu0_hotplug. 2265 2266config DEBUG_HOTPLUG_CPU0 2267 def_bool n 2268 prompt "Debug CPU0 hotplug" 2269 depends on HOTPLUG_CPU 2270 help 2271 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 2272 soon as possible and boots up userspace with CPU0 offlined. User 2273 can online CPU0 back after boot time. 2274 2275 To debug CPU0 hotplug, you need to enable CPU0 offline/online 2276 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 2277 compilation or giving cpu0_hotplug kernel parameter at boot. 2278 2279 If unsure, say N. 2280 2281config COMPAT_VDSO 2282 def_bool n 2283 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" 2284 depends on COMPAT_32 2285 help 2286 Certain buggy versions of glibc will crash if they are 2287 presented with a 32-bit vDSO that is not mapped at the address 2288 indicated in its segment table. 2289 2290 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a 2291 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and 2292 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is 2293 the only released version with the bug, but OpenSUSE 9 2294 contains a buggy "glibc 2.3.2". 2295 2296 The symptom of the bug is that everything crashes on startup, saying: 2297 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 2298 2299 Saying Y here changes the default value of the vdso32 boot 2300 option from 1 to 0, which turns off the 32-bit vDSO entirely. 2301 This works around the glibc bug but hurts performance. 2302 2303 If unsure, say N: if you are compiling your own kernel, you 2304 are unlikely to be using a buggy version of glibc. 2305 2306choice 2307 prompt "vsyscall table for legacy applications" 2308 depends on X86_64 2309 default LEGACY_VSYSCALL_XONLY 2310 help 2311 Legacy user code that does not know how to find the vDSO expects 2312 to be able to issue three syscalls by calling fixed addresses in 2313 kernel space. Since this location is not randomized with ASLR, 2314 it can be used to assist security vulnerability exploitation. 2315 2316 This setting can be changed at boot time via the kernel command 2317 line parameter vsyscall=[emulate|xonly|none]. 2318 2319 On a system with recent enough glibc (2.14 or newer) and no 2320 static binaries, you can say None without a performance penalty 2321 to improve security. 2322 2323 If unsure, select "Emulate execution only". 2324 2325 config LEGACY_VSYSCALL_EMULATE 2326 bool "Full emulation" 2327 help 2328 The kernel traps and emulates calls into the fixed vsyscall 2329 address mapping. This makes the mapping non-executable, but 2330 it still contains readable known contents, which could be 2331 used in certain rare security vulnerability exploits. This 2332 configuration is recommended when using legacy userspace 2333 that still uses vsyscalls along with legacy binary 2334 instrumentation tools that require code to be readable. 2335 2336 An example of this type of legacy userspace is running 2337 Pin on an old binary that still uses vsyscalls. 2338 2339 config LEGACY_VSYSCALL_XONLY 2340 bool "Emulate execution only" 2341 help 2342 The kernel traps and emulates calls into the fixed vsyscall 2343 address mapping and does not allow reads. This 2344 configuration is recommended when userspace might use the 2345 legacy vsyscall area but support for legacy binary 2346 instrumentation of legacy code is not needed. It mitigates 2347 certain uses of the vsyscall area as an ASLR-bypassing 2348 buffer. 2349 2350 config LEGACY_VSYSCALL_NONE 2351 bool "None" 2352 help 2353 There will be no vsyscall mapping at all. This will 2354 eliminate any risk of ASLR bypass due to the vsyscall 2355 fixed address mapping. Attempts to use the vsyscalls 2356 will be reported to dmesg, so that either old or 2357 malicious userspace programs can be identified. 2358 2359endchoice 2360 2361config CMDLINE_BOOL 2362 bool "Built-in kernel command line" 2363 help 2364 Allow for specifying boot arguments to the kernel at 2365 build time. On some systems (e.g. embedded ones), it is 2366 necessary or convenient to provide some or all of the 2367 kernel boot arguments with the kernel itself (that is, 2368 to not rely on the boot loader to provide them.) 2369 2370 To compile command line arguments into the kernel, 2371 set this option to 'Y', then fill in the 2372 boot arguments in CONFIG_CMDLINE. 2373 2374 Systems with fully functional boot loaders (i.e. non-embedded) 2375 should leave this option set to 'N'. 2376 2377config CMDLINE 2378 string "Built-in kernel command string" 2379 depends on CMDLINE_BOOL 2380 default "" 2381 help 2382 Enter arguments here that should be compiled into the kernel 2383 image and used at boot time. If the boot loader provides a 2384 command line at boot time, it is appended to this string to 2385 form the full kernel command line, when the system boots. 2386 2387 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 2388 change this behavior. 2389 2390 In most cases, the command line (whether built-in or provided 2391 by the boot loader) should specify the device for the root 2392 file system. 2393 2394config CMDLINE_OVERRIDE 2395 bool "Built-in command line overrides boot loader arguments" 2396 depends on CMDLINE_BOOL && CMDLINE != "" 2397 help 2398 Set this option to 'Y' to have the kernel ignore the boot loader 2399 command line, and use ONLY the built-in command line. 2400 2401 This is used to work around broken boot loaders. This should 2402 be set to 'N' under normal conditions. 2403 2404config MODIFY_LDT_SYSCALL 2405 bool "Enable the LDT (local descriptor table)" if EXPERT 2406 default y 2407 help 2408 Linux can allow user programs to install a per-process x86 2409 Local Descriptor Table (LDT) using the modify_ldt(2) system 2410 call. This is required to run 16-bit or segmented code such as 2411 DOSEMU or some Wine programs. It is also used by some very old 2412 threading libraries. 2413 2414 Enabling this feature adds a small amount of overhead to 2415 context switches and increases the low-level kernel attack 2416 surface. Disabling it removes the modify_ldt(2) system call. 2417 2418 Saying 'N' here may make sense for embedded or server kernels. 2419 2420source "kernel/livepatch/Kconfig" 2421 2422endmenu 2423 2424config ARCH_HAS_ADD_PAGES 2425 def_bool y 2426 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG 2427 2428config ARCH_ENABLE_MEMORY_HOTPLUG 2429 def_bool y 2430 depends on X86_64 || (X86_32 && HIGHMEM) 2431 2432config ARCH_ENABLE_MEMORY_HOTREMOVE 2433 def_bool y 2434 depends on MEMORY_HOTPLUG 2435 2436config USE_PERCPU_NUMA_NODE_ID 2437 def_bool y 2438 depends on NUMA 2439 2440config ARCH_ENABLE_SPLIT_PMD_PTLOCK 2441 def_bool y 2442 depends on X86_64 || X86_PAE 2443 2444config ARCH_ENABLE_HUGEPAGE_MIGRATION 2445 def_bool y 2446 depends on X86_64 && HUGETLB_PAGE && MIGRATION 2447 2448config ARCH_ENABLE_THP_MIGRATION 2449 def_bool y 2450 depends on X86_64 && TRANSPARENT_HUGEPAGE 2451 2452menu "Power management and ACPI options" 2453 2454config ARCH_HIBERNATION_HEADER 2455 def_bool y 2456 depends on HIBERNATION 2457 2458source "kernel/power/Kconfig" 2459 2460source "drivers/acpi/Kconfig" 2461 2462config X86_APM_BOOT 2463 def_bool y 2464 depends on APM 2465 2466menuconfig APM 2467 tristate "APM (Advanced Power Management) BIOS support" 2468 depends on X86_32 && PM_SLEEP 2469 help 2470 APM is a BIOS specification for saving power using several different 2471 techniques. This is mostly useful for battery powered laptops with 2472 APM compliant BIOSes. If you say Y here, the system time will be 2473 reset after a RESUME operation, the /proc/apm device will provide 2474 battery status information, and user-space programs will receive 2475 notification of APM "events" (e.g. battery status change). 2476 2477 If you select "Y" here, you can disable actual use of the APM 2478 BIOS by passing the "apm=off" option to the kernel at boot time. 2479 2480 Note that the APM support is almost completely disabled for 2481 machines with more than one CPU. 2482 2483 In order to use APM, you will need supporting software. For location 2484 and more information, read <file:Documentation/power/apm-acpi.rst> 2485 and the Battery Powered Linux mini-HOWTO, available from 2486 <http://www.tldp.org/docs.html#howto>. 2487 2488 This driver does not spin down disk drives (see the hdparm(8) 2489 manpage ("man 8 hdparm") for that), and it doesn't turn off 2490 VESA-compliant "green" monitors. 2491 2492 This driver does not support the TI 4000M TravelMate and the ACER 2493 486/DX4/75 because they don't have compliant BIOSes. Many "green" 2494 desktop machines also don't have compliant BIOSes, and this driver 2495 may cause those machines to panic during the boot phase. 2496 2497 Generally, if you don't have a battery in your machine, there isn't 2498 much point in using this driver and you should say N. If you get 2499 random kernel OOPSes or reboots that don't seem to be related to 2500 anything, try disabling/enabling this option (or disabling/enabling 2501 APM in your BIOS). 2502 2503 Some other things you should try when experiencing seemingly random, 2504 "weird" problems: 2505 2506 1) make sure that you have enough swap space and that it is 2507 enabled. 2508 2) pass the "no-hlt" option to the kernel 2509 3) switch on floating point emulation in the kernel and pass 2510 the "no387" option to the kernel 2511 4) pass the "floppy=nodma" option to the kernel 2512 5) pass the "mem=4M" option to the kernel (thereby disabling 2513 all but the first 4 MB of RAM) 2514 6) make sure that the CPU is not over clocked. 2515 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 2516 8) disable the cache from your BIOS settings 2517 9) install a fan for the video card or exchange video RAM 2518 10) install a better fan for the CPU 2519 11) exchange RAM chips 2520 12) exchange the motherboard. 2521 2522 To compile this driver as a module, choose M here: the 2523 module will be called apm. 2524 2525if APM 2526 2527config APM_IGNORE_USER_SUSPEND 2528 bool "Ignore USER SUSPEND" 2529 help 2530 This option will ignore USER SUSPEND requests. On machines with a 2531 compliant APM BIOS, you want to say N. However, on the NEC Versa M 2532 series notebooks, it is necessary to say Y because of a BIOS bug. 2533 2534config APM_DO_ENABLE 2535 bool "Enable PM at boot time" 2536 help 2537 Enable APM features at boot time. From page 36 of the APM BIOS 2538 specification: "When disabled, the APM BIOS does not automatically 2539 power manage devices, enter the Standby State, enter the Suspend 2540 State, or take power saving steps in response to CPU Idle calls." 2541 This driver will make CPU Idle calls when Linux is idle (unless this 2542 feature is turned off -- see "Do CPU IDLE calls", below). This 2543 should always save battery power, but more complicated APM features 2544 will be dependent on your BIOS implementation. You may need to turn 2545 this option off if your computer hangs at boot time when using APM 2546 support, or if it beeps continuously instead of suspending. Turn 2547 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 2548 T400CDT. This is off by default since most machines do fine without 2549 this feature. 2550 2551config APM_CPU_IDLE 2552 depends on CPU_IDLE 2553 bool "Make CPU Idle calls when idle" 2554 help 2555 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 2556 On some machines, this can activate improved power savings, such as 2557 a slowed CPU clock rate, when the machine is idle. These idle calls 2558 are made after the idle loop has run for some length of time (e.g., 2559 333 mS). On some machines, this will cause a hang at boot time or 2560 whenever the CPU becomes idle. (On machines with more than one CPU, 2561 this option does nothing.) 2562 2563config APM_DISPLAY_BLANK 2564 bool "Enable console blanking using APM" 2565 help 2566 Enable console blanking using the APM. Some laptops can use this to 2567 turn off the LCD backlight when the screen blanker of the Linux 2568 virtual console blanks the screen. Note that this is only used by 2569 the virtual console screen blanker, and won't turn off the backlight 2570 when using the X Window system. This also doesn't have anything to 2571 do with your VESA-compliant power-saving monitor. Further, this 2572 option doesn't work for all laptops -- it might not turn off your 2573 backlight at all, or it might print a lot of errors to the console, 2574 especially if you are using gpm. 2575 2576config APM_ALLOW_INTS 2577 bool "Allow interrupts during APM BIOS calls" 2578 help 2579 Normally we disable external interrupts while we are making calls to 2580 the APM BIOS as a measure to lessen the effects of a badly behaving 2581 BIOS implementation. The BIOS should reenable interrupts if it 2582 needs to. Unfortunately, some BIOSes do not -- especially those in 2583 many of the newer IBM Thinkpads. If you experience hangs when you 2584 suspend, try setting this to Y. Otherwise, say N. 2585 2586endif # APM 2587 2588source "drivers/cpufreq/Kconfig" 2589 2590source "drivers/cpuidle/Kconfig" 2591 2592source "drivers/idle/Kconfig" 2593 2594endmenu 2595 2596 2597menu "Bus options (PCI etc.)" 2598 2599choice 2600 prompt "PCI access mode" 2601 depends on X86_32 && PCI 2602 default PCI_GOANY 2603 help 2604 On PCI systems, the BIOS can be used to detect the PCI devices and 2605 determine their configuration. However, some old PCI motherboards 2606 have BIOS bugs and may crash if this is done. Also, some embedded 2607 PCI-based systems don't have any BIOS at all. Linux can also try to 2608 detect the PCI hardware directly without using the BIOS. 2609 2610 With this option, you can specify how Linux should detect the 2611 PCI devices. If you choose "BIOS", the BIOS will be used, 2612 if you choose "Direct", the BIOS won't be used, and if you 2613 choose "MMConfig", then PCI Express MMCONFIG will be used. 2614 If you choose "Any", the kernel will try MMCONFIG, then the 2615 direct access method and falls back to the BIOS if that doesn't 2616 work. If unsure, go with the default, which is "Any". 2617 2618config PCI_GOBIOS 2619 bool "BIOS" 2620 2621config PCI_GOMMCONFIG 2622 bool "MMConfig" 2623 2624config PCI_GODIRECT 2625 bool "Direct" 2626 2627config PCI_GOOLPC 2628 bool "OLPC XO-1" 2629 depends on OLPC 2630 2631config PCI_GOANY 2632 bool "Any" 2633 2634endchoice 2635 2636config PCI_BIOS 2637 def_bool y 2638 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2639 2640# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2641config PCI_DIRECT 2642 def_bool y 2643 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2644 2645config PCI_MMCONFIG 2646 bool "Support mmconfig PCI config space access" if X86_64 2647 default y 2648 depends on PCI && (ACPI || JAILHOUSE_GUEST) 2649 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) 2650 2651config PCI_OLPC 2652 def_bool y 2653 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2654 2655config PCI_XEN 2656 def_bool y 2657 depends on PCI && XEN 2658 select SWIOTLB_XEN 2659 2660config MMCONF_FAM10H 2661 def_bool y 2662 depends on X86_64 && PCI_MMCONFIG && ACPI 2663 2664config PCI_CNB20LE_QUIRK 2665 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2666 depends on PCI 2667 help 2668 Read the PCI windows out of the CNB20LE host bridge. This allows 2669 PCI hotplug to work on systems with the CNB20LE chipset which do 2670 not have ACPI. 2671 2672 There's no public spec for this chipset, and this functionality 2673 is known to be incomplete. 2674 2675 You should say N unless you know you need this. 2676 2677config ISA_BUS 2678 bool "ISA bus support on modern systems" if EXPERT 2679 help 2680 Expose ISA bus device drivers and options available for selection and 2681 configuration. Enable this option if your target machine has an ISA 2682 bus. ISA is an older system, displaced by PCI and newer bus 2683 architectures -- if your target machine is modern, it probably does 2684 not have an ISA bus. 2685 2686 If unsure, say N. 2687 2688# x86_64 have no ISA slots, but can have ISA-style DMA. 2689config ISA_DMA_API 2690 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2691 default y 2692 help 2693 Enables ISA-style DMA support for devices requiring such controllers. 2694 If unsure, say Y. 2695 2696if X86_32 2697 2698config ISA 2699 bool "ISA support" 2700 help 2701 Find out whether you have ISA slots on your motherboard. ISA is the 2702 name of a bus system, i.e. the way the CPU talks to the other stuff 2703 inside your box. Other bus systems are PCI, EISA, MicroChannel 2704 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2705 newer boards don't support it. If you have ISA, say Y, otherwise N. 2706 2707config SCx200 2708 tristate "NatSemi SCx200 support" 2709 help 2710 This provides basic support for National Semiconductor's 2711 (now AMD's) Geode processors. The driver probes for the 2712 PCI-IDs of several on-chip devices, so its a good dependency 2713 for other scx200_* drivers. 2714 2715 If compiled as a module, the driver is named scx200. 2716 2717config SCx200HR_TIMER 2718 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2719 depends on SCx200 2720 default y 2721 help 2722 This driver provides a clocksource built upon the on-chip 2723 27MHz high-resolution timer. Its also a workaround for 2724 NSC Geode SC-1100's buggy TSC, which loses time when the 2725 processor goes idle (as is done by the scheduler). The 2726 other workaround is idle=poll boot option. 2727 2728config OLPC 2729 bool "One Laptop Per Child support" 2730 depends on !X86_PAE 2731 select GPIOLIB 2732 select OF 2733 select OF_PROMTREE 2734 select IRQ_DOMAIN 2735 select OLPC_EC 2736 help 2737 Add support for detecting the unique features of the OLPC 2738 XO hardware. 2739 2740config OLPC_XO1_PM 2741 bool "OLPC XO-1 Power Management" 2742 depends on OLPC && MFD_CS5535=y && PM_SLEEP 2743 help 2744 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2745 2746config OLPC_XO1_RTC 2747 bool "OLPC XO-1 Real Time Clock" 2748 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2749 help 2750 Add support for the XO-1 real time clock, which can be used as a 2751 programmable wakeup source. 2752 2753config OLPC_XO1_SCI 2754 bool "OLPC XO-1 SCI extras" 2755 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y 2756 depends on INPUT=y 2757 select POWER_SUPPLY 2758 help 2759 Add support for SCI-based features of the OLPC XO-1 laptop: 2760 - EC-driven system wakeups 2761 - Power button 2762 - Ebook switch 2763 - Lid switch 2764 - AC adapter status updates 2765 - Battery status updates 2766 2767config OLPC_XO15_SCI 2768 bool "OLPC XO-1.5 SCI extras" 2769 depends on OLPC && ACPI 2770 select POWER_SUPPLY 2771 help 2772 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2773 - EC-driven system wakeups 2774 - AC adapter status updates 2775 - Battery status updates 2776 2777config ALIX 2778 bool "PCEngines ALIX System Support (LED setup)" 2779 select GPIOLIB 2780 help 2781 This option enables system support for the PCEngines ALIX. 2782 At present this just sets up LEDs for GPIO control on 2783 ALIX2/3/6 boards. However, other system specific setup should 2784 get added here. 2785 2786 Note: You must still enable the drivers for GPIO and LED support 2787 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2788 2789 Note: You have to set alix.force=1 for boards with Award BIOS. 2790 2791config NET5501 2792 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2793 select GPIOLIB 2794 help 2795 This option enables system support for the Soekris Engineering net5501. 2796 2797config GEOS 2798 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2799 select GPIOLIB 2800 depends on DMI 2801 help 2802 This option enables system support for the Traverse Technologies GEOS. 2803 2804config TS5500 2805 bool "Technologic Systems TS-5500 platform support" 2806 depends on MELAN 2807 select CHECK_SIGNATURE 2808 select NEW_LEDS 2809 select LEDS_CLASS 2810 help 2811 This option enables system support for the Technologic Systems TS-5500. 2812 2813endif # X86_32 2814 2815config AMD_NB 2816 def_bool y 2817 depends on CPU_SUP_AMD && PCI 2818 2819config X86_SYSFB 2820 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2821 help 2822 Firmwares often provide initial graphics framebuffers so the BIOS, 2823 bootloader or kernel can show basic video-output during boot for 2824 user-guidance and debugging. Historically, x86 used the VESA BIOS 2825 Extensions and EFI-framebuffers for this, which are mostly limited 2826 to x86. 2827 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2828 framebuffers so the new generic system-framebuffer drivers can be 2829 used on x86. If the framebuffer is not compatible with the generic 2830 modes, it is advertised as fallback platform framebuffer so legacy 2831 drivers like efifb, vesafb and uvesafb can pick it up. 2832 If this option is not selected, all system framebuffers are always 2833 marked as fallback platform framebuffers as usual. 2834 2835 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2836 not be able to pick up generic system framebuffers if this option 2837 is selected. You are highly encouraged to enable simplefb as 2838 replacement if you select this option. simplefb can correctly deal 2839 with generic system framebuffers. But you should still keep vesafb 2840 and others enabled as fallback if a system framebuffer is 2841 incompatible with simplefb. 2842 2843 If unsure, say Y. 2844 2845endmenu 2846 2847 2848menu "Binary Emulations" 2849 2850config IA32_EMULATION 2851 bool "IA32 Emulation" 2852 depends on X86_64 2853 select ARCH_WANT_OLD_COMPAT_IPC 2854 select BINFMT_ELF 2855 select COMPAT_OLD_SIGACTION 2856 help 2857 Include code to run legacy 32-bit programs under a 2858 64-bit kernel. You should likely turn this on, unless you're 2859 100% sure that you don't have any 32-bit programs left. 2860 2861config IA32_AOUT 2862 tristate "IA32 a.out support" 2863 depends on IA32_EMULATION 2864 depends on BROKEN 2865 help 2866 Support old a.out binaries in the 32bit emulation. 2867 2868config X86_X32 2869 bool "x32 ABI for 64-bit mode" 2870 depends on X86_64 2871 help 2872 Include code to run binaries for the x32 native 32-bit ABI 2873 for 64-bit processors. An x32 process gets access to the 2874 full 64-bit register file and wide data path while leaving 2875 pointers at 32 bits for smaller memory footprint. 2876 2877 You will need a recent binutils (2.22 or later) with 2878 elf32_x86_64 support enabled to compile a kernel with this 2879 option set. 2880 2881config COMPAT_32 2882 def_bool y 2883 depends on IA32_EMULATION || X86_32 2884 select HAVE_UID16 2885 select OLD_SIGSUSPEND3 2886 2887config COMPAT 2888 def_bool y 2889 depends on IA32_EMULATION || X86_X32 2890 2891if COMPAT 2892config COMPAT_FOR_U64_ALIGNMENT 2893 def_bool y 2894 2895config SYSVIPC_COMPAT 2896 def_bool y 2897 depends on SYSVIPC 2898endif 2899 2900endmenu 2901 2902 2903config HAVE_ATOMIC_IOMAP 2904 def_bool y 2905 depends on X86_32 2906 2907source "drivers/firmware/Kconfig" 2908 2909source "arch/x86/kvm/Kconfig" 2910 2911source "arch/x86/Kconfig.assembler" 2912